Battery charger operating method and method usable with plural different power supplies

ABSTRACT

A method for charging a battery may comprise: setting an initial low charge current level; repetitively interrupting charging in a periodic cycle, and: measuring an open circuit battery voltage when charging is interrupted, determining from the open circuit battery voltage a corresponding charging current; applying the predetermined charging current; and repeating the periodic cycle. A method may also comprise: setting an initial charge current level, determining the current available by measuring the supply voltage, and decreasing the charging current level if the measured supply voltage is less than a predetermined voltage.

This Application is a division of U.S. patent application Ser. No.15/053,539 filed Feb. 25, 2016 entitled “USB CONNECTOR USABLE WITH ABATTERY CHARGER AND OTHERWISE,” and is also a division of U.S. patentapplication Ser. No. 15/053,606 filed Feb. 25, 2016 entitled “BATTERYCHARGER USABLE WITH PLURAL DIFFERENT POWER SUPPLIES,” both of whichclaim the benefit of U.S. Provisional Application Ser. No. 62/249,606filed Nov. 2, 2015 entitled “BATTERY CHARGER USABLE WITH PLURALDIFFERENT POWER SUPPLIES,” and of U.S. Provisional Application Ser. No.62/132,037 filed Mar. 12, 2015 entitled “BATTERY CHARGER USABLE WITHPLURAL DIFFERENT POWER SUPPLIES,” each of which is hereby incorporatedherein by reference in its entirety.

In one aspect, the invention relates to a method for charging one ormore batteries. The invention also relates to a method for operating abattery charger.

In another aspect, the invention may relate to a connector arrangementusable with the battery charger and otherwise. In yet another aspect,the present invention may relate to a battery charger and, inparticular, to a battery charger usable with plural different powersupplies.

As the size and power requirements of electronic circuitry has shrunkand the energy storage capacity of batteries per unit volume hasincreased, more and more types of electronic devices shrink in size andbecome more portable, thus lending themselves to charging from lowerpower capacity power supply devices as well as from conventional powersupplies. Typically power supplies have distinctive connectors, or avariety of relatively standardized power connectors, e.g., coaxialcontact connectors of different voltages, currents, polarity anddiameters, and so are not interchangeable with each other.

Also, as more electronic devices transmit and receive data viaconnecting cables, and to and from external memory devices, e.g.,external drives and “thumb” or flash drives, a standardized interfacecalled a universal serial bus (USB) interface has become the standardfor interconnection with and between electronic devices. The USBinterface includes a pair of male and female mating connectors that havepower pins for +5 volts DC and ground or return, and two pins for datatransmission.

While the current available from the +5 Volt DC (herein VDC) USBconnector power supply pin can vary greatly, e.g., from a standard levelof one hundred milliamperes, e.g., from a device such as a laptopcomputer, but possibly to a greater current, e.g., up to about 1.8 orabout 2.4 amperes from a power supply, it is usually able to provide alevel of current that is sufficient for recharging a rechargeablebattery, even if at a less than optimum or less than maximum chargerate. The longer charging time is often an acceptable penalty inexchange for the convenience of using an available USB port to rechargea device.

In another aspect, conventional USB connectors, such as those usablewith battery charging, can be damaged relatively easily if not properlyaligned and/or oriented when being connected, e.g., mated with acompatible connector, and also may be subject to being dislodged orde-mated unintentionally.

Applicant believes there may be a need for a battery charger and for amethod for operating a battery charger that addresses some or all of theforegoing battery charger related aspects. In addition, Applicant alsobelieves there may be a need for a connector that addresses some or allof the foregoing connector related aspects.

Accordingly, a battery charger may comprise: a housing having at leastone cradle; a connector port for receiving at different times electricalplug connectors having different contact configurations; electricalreceptacles in the connector port for receiving at different timeselectrical plug connectors associated with different electrical powersupplies; a first electrical receptacle having a different contactconfiguration than a second electrical receptacle; the electricalreceptacles being closely adjacent such that an electrical connectorinserted into one of the electrical receptacles physically prevents anelectrical connector from being inserted into the other electricalreceptacle; and an electrical circuit coupling electrical power receivedat the electrical receptacles to the at least one cradle.

In another aspect, an electrical connector may comprise: an elongatedconnector body with an electrical connector frame at one end thereof;the connector body having a longitudinal alignment feature, a guidefeature defining an orientation, and a retaining feature.

An electrical connector may comprise: an electrical connector framesupported on a base; an alignment and retaining structure includingfirst and second opposing guide members configured for an elongatedconnector body to be placed therebetween to mate with the electricalconnector frame; the first guide member configured to align acomplementary feature of the connector body and to receive a guidefeature on the connector body that defines an orientation; and at leastone of the first and second guide members having a retaining featureconfigured to engage the connector body for retaining the elongatedconnector body between the first and second guide members with theconnector body mated with the electrical connector frame.

In yet another aspect, a method for charging a battery may comprise:

-   -   a) determining whether a battery is present;    -   b) setting an initial charge current level;    -   c) repetitively interrupting charging of the battery at a        predetermined timing to define a periodic cycle, and for each        periodic cycle:        -   measuring an open circuit voltage of the battery when            charging of the battery is interrupted,        -   determining from the measured open circuit voltage a level            of charging current;        -   applying charging current to the battery; and    -   d) repeating the periodic cycle at least until the open circuit        voltage is at a voltage indicative of the battery being fully        charged or until the battery is disconnected.

According to another aspect, a method for charging a rechargeablebattery may comprise:

-   -   a) determining whether a battery is present;    -   b) setting an initial charge current level;    -   c) determining the current available from an external power        supply including:        -   i) measuring a voltage provided by the external power            supply;        -   ii) determining whether the external power supply voltage is            less than a predetermined voltage and, if so:        -   iii) decreasing the current drawn from the external power            supply;    -   d) repeating the foregoing steps of i) measuring, ii)        determining and iii) decreasing until the external power supply        voltage is not less than the predetermined voltage.

According to a further aspect, a method for charging a rechargeablebattery may comprise:

-   -   a) determining whether a battery is present;    -   b) setting an initial charge current level;    -   c) determining the current available from an external power        supply including:        -   i) measuring a voltage provided by the external power            supply;        -   ii) determining whether the external power supply voltage is            less than a predetermined voltage and, if so:        -   iii) decreasing the current drawn from the external power            supply;    -   d) repeating the foregoing steps of i) measuring, ii)        determining and iii) decreasing until the external power supply        voltage is not less than the predetermined voltage; and    -   e) repetitively interrupting charging of the battery at a        predetermined timing to define a periodic cycle, and for each        periodic cycle:        -   i) measuring an open circuit voltage of the battery when            charging of the battery is interrupted,        -   ii) determining from the measured open circuit voltage a            level of charging current;        -   iii) applying charging current to the battery; and    -   f) repeating the periodic cycle at least until the open circuit        voltage is at a voltage indicative of the battery being fully        charged or until the battery is disconnected.

In summarizing the arrangements described and/or claimed herein, aselection of concepts and/or elements and/or steps that are described inthe detailed description herein may be made or simplified. Any summaryis not intended to identify key features, elements and/or steps, oressential features, elements and/or steps, relating to the claimedsubject matter, and so are not intended to be limiting and should not beconstrued to be limiting of or defining of the scope and breadth of theclaimed subject matter.

BRIEF DESCRIPTION OF THE DRAWING

The detailed description of the preferred embodiment(s) will be moreeasily and better understood when read in conjunction with the FIGURESof the Drawing which include:

FIGS. 1A, 1B and 1C are three different perspective views of an exampleembodiment of a battery charger having a rechargeable electronic deviceand a rechargeable battery in respective cradles thereof;

FIGS. 2A and 2B are front views of the example embodiment of a batterycharger of FIG. 1 with and without the rechargeable electronic devicelight and the rechargeable battery in the respective cradles thereof;

FIG. 3 is a side cross-sectional view of the example embodiment of abattery charger of FIGS. 1 and 2 with a rechargeable electronic devicein one cradle thereof and a rechargeable battery in another cradlethereof;

FIG. 4A is a view of the bottom end of example embodiment of the batterycharger of FIGS. 1-3 and FIG. 4B which is an enlargement of a portion ofFIG. 4A showing a connector port thereof;

FIGS. 5A and 5B are respective views of the connector port on the bottomend of the example embodiment of a battery charger with each of twodifferent plug connectors inserted therein;

FIGS. 6A, 6B and 6C are a perspective view and two different side views,respectively, of the connector port on the bottom end of the exampleembodiment of a battery charger including an example embodiment of aconnector alignment arrangement;

FIGS. 7A, 7B and 7C are respective perspective views of an exampleembodiment of an alternative connector, and of the alternative connectorpartially inserted and fully inserted in the connector port of theexample embodiment of a battery charger including an example embodimentof an alignment and retaining arrangement, and FIG. 7D is across-sectional view of the example connector in a mated configuration;

FIG. 8 includes two perspective views and four orthogonal views of theexample embodiment of alternative connector of FIG. 7 including anexample embodiment of an alignment and retaining arrangement;

FIG. 9 is an electrical schematic diagram of an example embodiment of anelectrical circuit suitable for use with the example embodiment of abattery charger of FIGS. 1-6C, and FIG. 9A is an alternative exampleembodiment of the example electrical circuit of FIG. 9;

FIGS. 10 and 10A are schematic flow diagrams illustrating an example ofthe operation of the example embodiment of a battery charger andelectrical circuit of FIGS. 1-9A; and

FIGS. 11A, 11B and 11C are together a single schematic flow diagramillustrating an alternative example of the operation of the exampleembodiment of a battery charger and electrical circuit of FIGS. 1-9A.

In the Drawing, where an element or feature is shown in more than onedrawing figure, the same alphanumeric designation may be used todesignate such element or feature in each figure, and where a closelyrelated or modified element is shown in a figure, the samealphanumerical designation primed or the like may be used to designatethe modified element or feature. Similarly, similar elements or featuresmay be designated by like alphanumeric designations in different figuresof the Drawing. and with similar nomenclature in the specification. Asis common, the various features of the drawing are not to scale, thedimensions of the various features may be arbitrarily expanded orreduced for clarity, and any value stated in any Figure is given by wayof example only.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

FIGS. 1A, 1B and 1C are three different perspective views of an exampleembodiment of a battery charger 100 having a rechargeable electronicdevice 180 and a rechargeable battery 190 in respective cradles 110, 120thereof; and FIGS. 2A and 2B are front views of the example embodimentof a battery charger 100 of FIG. 1 with and without the rechargeableelectronic device 180, e.g., a flashlight 180, and the rechargeablebattery 190 in the respective cradles 110, 120 thereof. FIG. 3 is a sidecross-sectional view of the example embodiment of a battery charger 100of FIGS. 1 and 2 with a rechargeable electronic device 180 in one cradle110 thereof and a rechargeable battery 190 in another cradle 120thereof.

The example embodiment 100 illustrated is a Streamlight STRION PiggybackBattery Charger 100 that has two receptacles 110, 120 or cradles 110,120—one 110 for charging a battery or battery pack within a flashlight180 that is placed into the receptacle 110 and a second 120 for charginga battery 190 or battery pack 190 apart from a flashlight 180, e.g.,typically the battery packs 190 are of the same type with each being areplacement for the other. Charger 100 receives electrical power fromeither of two different electrical power supplies via connector port150:

-   -   A 12/18/24 volt DC power source that connects, e.g., to a DC        vehicle system or to another source that connects to AC power        mains, and    -   A USB power source, sometimes connected to a power “cube” or        “block” that provides, e.g., +5 volts DC, or to a device, e.g.,        a personal computer, that provides, e.g., +5 VDC, at a USB port.

Charger 100 has a generally rectangular base 130 or housing 130 fromwhich a pair of spring-biased arms 112 extend to define a first cradle110 having electrical contacts 116. When placed into the first cradle110, an electronic device, e.g., flashlight 180, is retained therein bythe spring-biased arms 112 and electrically connects to the circuitry200 of the charger 100 to receive charging current via correspondingelectrical contacts 116. A second or auxiliary cradle 120 is defined,e.g., along one side of the rectangular housing 130 to receive a battery190, e.g., a battery 190 or battery pack 190 apart from a flashlight,such as an auxiliary battery or a spare battery, which is retainedtherein to electrically connect to the circuitry 200 of the charger 100to receive charging current via corresponding electrical contacts 116.The charger electrical circuitry 200 is contained and supported withinthe charger base 130.

First and second electrical receptacles 152, 154, e.g., electricalconnectors 152, 154, are provided in a charger connector port 150, e.g.,an opening 150 in the charger base 130, e.g., on the bottom sidethereof, for receiving connectors of electrical cables from two or moredifferent electrical power supplies. Preferably, one opening or port 150in the charger base 130 provides access to plural electrical connectors162, 164, e.g., two electrical connectors 152, 154, and the one opening150 is configured so that the external outlines of the plural, e.g.,two, different electrical power supply connectors 162, 164 cannot beconnected to the charger base 130 at the same time. In other words, wheneither one of the plural, e.g., two, cable connectors 162, 164 isplugged into its corresponding connector 152, 154 in the port 150 of thecharger base 130 it overlaps in part the other connector or connectors152, 154 thereof so that the plugged in connector 162, 164 mechanicallyinterferes with and prevents another cable connector 162, 164 from beingplugged into its corresponding connector 152, 154 in the connector port150.

An example of such connector opening or port 150 having first and secondelectrical receptacles 152, 154 for receiving at different times firstand second electrical connectors 162, 164, e.g., an AC or DC powersupply connector 162 and a USB connector 164, is described below inrelation to FIGS. 4 and 5. Power source 160 typically includes one ofelectrical connectors 162, 164 that connect via a respective electricalcable 166 to a respective power source 168, which in the Figurerepresent any one of several external power sources 168, including a USBpower source 168.

Charger housing or base 130 includes a housing body 132 having anopening on the underside thereof that is covered by a housing base 134.A pair of arm supports 136 extend from the face of charger housing body132 and provide respective pivotable joints at which spring arms 112 arepivotably attached 137, e.g., by a pivot pin 137, to arm supports 136 ofhousing body 132. Spring arms 112 are biased by respective springs topivot towards each other and have respective opposing sloped surfaces atthe ends thereof distal the pivot pins 137 to facilitate flashlight 180being placed into cradle 110 with a snap-in motion. That is, whenflashlight 180 is pressed against the sloped surfaces of spring arms112, spring arms 112 move away from each other against the spring biasto allow flashlight 180 to move into cradle 110 whereupon spring-biasedarms 112 move closer to each other to retain flashlight 180 in cradle110 (as illustrated by double-ended arrows). Thus, an electrical device180 may conveniently be quickly snapped into cradle 110 and snapped outof cradle 110.

Preferably, flashlight 180 is guided to a predetermined position incradle 110 whereat charging contacts of flashlight 180 make electricalconnection to electrical charging contacts 116 within cradle 110. Cradle110 preferably has a triangular guide member 114, e.g., a triangularrecess 114, that corresponds to a corresponding triangular guide member,e.g., a triangular raised feature, of flashlight 180. When thecorresponding guide members of cradle 110 and flashlight 180 engage eachother, the electrical charging contacts 189 of flashlight 180 are inelectrical contact with electrical charging contacts 116 of charger 100,as illustrated in FIGS. 2B and 3.

An optional auxiliary or “piggyback” secondary housing 140 may beattached to charger housing 130 in which position it is electricallyconnected to the circuitry of charger 100 for charging a rechargeablebattery 190 which may be placed into cradle 120 of housing 140.Connection end 142 of housing 140 includes electrical contacts formaking electrical connection to electrical contacts of rechargeablebattery 190. An example of a suitable contact arrangement may be foundin, e.g., U.S. Pat. No. 6,652,115 entitled “BATTERY CHARGER STRUCTUREAND RECHARGEABLE FLASHLIGHT SYSTEM USING THE SAME” issued Nov. 25, 2003,which is assigned to Streamlight, Inc., the assignee of the presentApplication, and which is hereby incorporated herein by reference in itsentirety.

An indicator light 138, e.g., a light emitting diode (LED) 138, oncharger housing 130 provides a visual indication of the status of thecharging being provided via cradle 110 when an electronic device 180 isdisposed therein. Similarly, an indicator light 148, e.g., a lightemitting diode 148, on secondary charger housing 140 provides a visualindication of the status of the charging being provided via cradle 120when a rechargeable battery 190 is disposed therein. Either or both ofindicators 138, 148 may be a light emitting diode or may include anoptical light pipe coupled to light emitting diodes within charger base130 and secondary housing 140, respectively.

Example electronic device 180 may be a flashlight 180 having a devicehousing 182 with a light head 184 at a forward end thereof and a barrel186 toward a rearward end thereof, with an actuator 188 at the rearwardend thereof for controlling operation of flashlight 180. Light head 184includes a light source, e.g., a light emitting diode 184L and areflector 185R that forms the light from LED 184L into a desired beamshape which exits via lens 185. A rechargeable battery 190 may bedisposed within barrel 186 and actuator 188 may actuate an electricalswitch within flashlight housing 182 for controlling the operation offlashlight 180.

As illustrated in FIG. 3, housing base 134 is retained to the undersideof housing body 132 by one or more threaded or other fasteners and anelectronic circuit board 200 is disposed in housing 130. Chargingcontacts 116 are spring biased by respective springs, e.g., helicalsprings, surrounding the respective bases thereof so as to be urgedoutward toward the position in the first cradle 110 whereat thecorresponding charging contacts 189 of flashlight 180 are positionedwhen flashlight 180 is seated in cradle 110. Contacts 116 are connectedto the circuitry of circuit board 200 by respective electrical wires 202for conducting charging current to electronic device 180, e.g.,flashlight 180, via contacts 116 and for sensing the voltage of thebattery 190 therein, as described below. Piggyback or secondary chargerhousing 140 may attach to charger housing 130 by its base serving inplace of the base 134 of housing 140 and being fastened thereto by oneor more fasteners, e.g., self-tapping screws. Secondary charger housing140 may connect electrically by plural electrical conductors, e.g.,wires, connected between an electronic circuit board mounted insecondary housing 140 and the electronic circuit board 200 mounted inhousing 130.

Device 180 is seen to have two coaxial helical springs extendingrearward from the forward or light head 184 end thereof for makingelectrical connection to a central contact and to a surrounding annularcontact at the forward end of battery 190. Actuator 188 is seen to havea central region that actuates a switch 188S via a spring and plungerthat are contained within the tail cap 186T that is on the end of barrel186 of housing 182 of flashlight 180. Switch 188S may be connected bybarrel 186 providing one electrical conductor and by battery 190providing a second electrical conductor via a spring of switch 188S andan electrical contact at the rearward end of battery 190.

FIG. 4A is a view of the bottom end of example embodiment of a batterycharger 100 of FIGS. 1-3 and FIG. 4B is an enlargement of a portion ofFIG. 4A showing a connector port 150 thereof; and FIGS. 5A and 5B arerespective views of the connector port 150 on the bottom end of theexample embodiment of a battery charger 100 with each of two differentplug connectors 162, 164 inserted therein.

Connector 152 is, e.g., a connector having two receptacle contacts 152Cfor receiving a two prong plug 162 associated with a DC power source,e.g., such as ones available from Streamlight, Inc., located inEagleville, Pa., that provide a DC voltage in the range of about 10 to24 VDC. These connectors 152, 162 are keyed by a rectangular recess onconnector 152 that corresponds with a rectangular projection ofconnector 162 so that the two connectors 152, 162 can mate in only oneorientation so as to provide proper polarity DC voltage to charger 100,e.g., to circuit board 200 thereof. Preferably a shroud or framesurrounds the contacts of connectors 152, 154 so as to reduce thelikelihood of their inadvertently coming in to electrical contact withother than the recessed receptacle contacts 152C of connector 152.

Connector 154 is, e.g., a USB connector, having four contacts 154C forreceiving a USB plug 164 associated with a USB DC power source, e.g.,such as ones available from Streamlight, Inc., of Eagleville, Pa., aswell as from many other sources. USB power sources provide a DC voltageof about 5.0 VDC on two of the connections and can provide signalsand/or data on the remaining connections. These connectors 154, 164 arekeyed by a shaped rectangular frame on connector 154 that correspondswith a shaped rectangular frame of connector 164 so that the connectors154, 164 can mate in only one orientation so as to provide properpolarity DC voltage to charger 100, e.g., to circuit board 200 thereof.The respective frames surround the contacts of connectors 154, 164 so asto reduce the likelihood of their inadvertently coming in to electricalcontact other than with the mating contacts of another USB connector154, 164. Typically, connector 154 is a female USB connector andconnector 164 is a male USB connector.

Connector port 150 is shaped so that the respective shells of connectors162, 164 physically block the other connector 164, 162 from beingconnected to connector port when one of connectors 162, 164 is connectedthereto. Connector 162 has a shell whose outline 163 is indicated by adashed rectangle surrounding connector 152 and connector 164 has a shellwhose outline 165 is indicated by a dashed rectangle surroundingconnector 154 to illustrate that the respective shells 163, 165physically interfere to prevent both being connected to charger 100 atthe same time. Specifically, the shell 163 of connector 162 blocks theshell 165 of connector 164 and so prevents connector 164 from beingmated with connector 154, and the shell 165 of connector 164 blocks theshell 163 of connector 162 and so prevents connector 162 from beingmated with connector 152.

FIGS. 6A, 6B and 6C are a perspective view and two different side views,respectively, of the connector port 150 on the bottom end of the exampleembodiment of a battery charger 100 including an example embodiment of aconnector alignment arrangement 156. USB connector 164 is illustrated asbeing plugged in to USB connector 154 of connector port 150. Many USBconnectors can easily be attempted to be connected with the USB plug 164when misaligned from the USB receptacle 154 which can damage either orboth connectors. Alignment arrangement 156 includes a plurality ofguides 156 that extend outwardly from housing 130 around USB connector154 to define a guide path to decrease any misalignment of USB plug 164before it comes into mating position with USB connector 154, thereby toreduce the risk of damage.

The plurality of guides 156 provided extend outwardly from housing 130,e.g., substantially perpendicularly to the surface of housing 130 aroundUSB connector 154 so as to be adjacent to USB plug 164 when USB plug 164is plugged into USB connector 154 or is being plugged into connector154. Guides 156 preferably are spaced apart a distance that is slightlygreater than the transverse dimensions of connector 164 so that the bodyof connector 164 is constrained by the spacing between guides 156 to besubstantially aligned with connector 154 as the two are moved closertogether for mating.

In the illustrated example arrangement, e.g., three guides 156 areprovided, one guide 156 adjacent a narrow side of connectors 152, 164and two opposing guides 156 adjacent the two wider sides of connector154, 164. The latter two guides may be, and preferably are, U-shapedwhen viewed on end, e.g., for increasing their resistance to breakage.The function of a guide 156 at the other narrow side of connector 152,164 in this example embodiment is provided by the body of connector 152which extends outwardly form housing 130, however, it could be providedby another guide 156.

FIGS. 7A, 7B and 7C are respective perspective views of an exampleembodiment of an alternative connector 164, 300 and of the alternativeconnector 164, 300 partially inserted and fully inserted in theconnector port 150, 156 of the example embodiment of a battery charger100 including an example embodiment of an alignment and retainingarrangement 156, and FIG. 7D is a cross-sectional view of the exampleconnector 300 in a mated configuration; and FIG. 8 includes twoperspective views and four orthogonal views of the example embodiment ofan alternative connector 164, 300 of FIG. 7 including an exampleembodiment of an alignment and retaining arrangement 156.

Connector 164, 300 includes a connector body 310 that is, e.g., moldedover the electrical elements of a connector, e.g., a USB connector frame164P, to which is connected an electrical cable 166 over which body 310is preferably also over-molded. The rear end of body 310, i.e. the enddistal connector frame 164P, tapers narrower and has a plurality ofrecesses 312 for reducing the strain between cable 166 and body 310where cable 166 enters body 310. Strain relief 312 reduces the strainand thus renders the exterior surface of cable 166 less likely toseparate from the molded material of body 310. Connector body 310preferably also has one or more gripping features 314, 316, e.g.,ridges, bumps and/or recesses 314, 316, on opposing faces thereof tofacilitate insertion and removal of connector 300 from its matingconnector.

The forward end of connector body 310, i.e. the end proximal connectorframe 164P, preferably has one or more features 320, 330, 340 forfacilitating the alignment of connector 300 for insertion into itsmating connector, e.g., a connector 154. In particular, features 320,330, 340 cooperate with guides 156, 400 and corresponding featuresthereof to require the substantial alignment of connector 300 forinsertion into its mating connector, e.g., a connector 154, of base 130Bto prevent connector frame 164P from entering its mating connector,e.g., a connector 154, if in reversed orientation, and to retainconnector 300 in position with connector frame 164P mated with itsmating connector, e.g., a connector 154.

Accordingly, connector 300 preferably has at least one alignment feature320, e.g., an alignment rib 320, and guides 156, 400 preferably have atleast one corresponding alignment feature 420, e.g., an alignment groove420, for substantially aligning the respective longitudinal axes ofconnector 300 and its mating connector, e.g., a connector 154, at leastin one axis, for proper mating.

Connector 300 preferably includes at least one raised guide 330 forallowing connector 300 to enter guides 400, which includes opposingguides 156 which extend from base 130B and are spaced apart by adistance that is slightly greater than the dimension of connector body310, but less than the combined dimension of connector body 310 andraised guide 330 thereon, only if in the proper orientation whereinraised guide 330 becomes disposed in alignment groove 420 upon matingand so cannot be inserted in an inverted orientation.

Connector 300 preferably also includes one or more retaining features340, e.g., transverse retaining ribs 340, complementary to one or morecorresponding retaining features, e.g., transverse retaining grooves440, of guides 156, 400 so that retaining ribs 340 become disposed inretaining grooves 440 when connector 300 is fully mated with its matingconnector, for retaining connector 300 in mating connection with itsmating connector, e.g., a connector 154. One or more retaining features340 may be provided on one or more surfaces of connector body 310, andalternatively, the ribs 340 could be provided on guides 400 and thegrooves 440 could be provided on connector 300.

Guides or guide members 156, 400 of this example embodiment arepreferably “C-shaped” when viewed from the end. Guides 156, 400 providetwo opposing broad inward facing surfaces that are adjacent to and guidethe two opposing broad outer surfaces of connector body 310 and are ofsufficient thickness to provide strength and to provide groove 420 andrecesses 440 on at least one of the inward facing surfaces thereof. Theremote ends of the C-shaped guides 156, 400 bend around and are adjacentto the two opposing narrow sides of connector body 310 and guide the twoopposing narrow sides of connector body 310 during mating and de-matingof connector 164, 300 and, e.g., its mating connector 154.

In one example embodiment of a connector 300, the over-molded plughousing 310 including raised guide 330 and alignment rib 320 is aslip-fit into guide 400 with the engagement of retaining rib 340 andretaining groove 440 being more of an interference or snap-fit withguide 400. The slip-fit tolerance is selected to be close enough toguide the connector 300 and prevent accidental damage thereto whileallowing proper insertion depth for the proper mating of connectors 164,154. The position of the retaining rib or ribs 340 relative to retaininggrooves 440 determines the insertion depth for a given connector types,and will be different for different connector types, and so thedimensions and tolerances selected must relate to or comply with theparticular connector and/or connector standard chosen for theapplication.

For example: where the charger 100 employs a Micro-B type USB connectorconfiguration, connector body 310 and guide 400 will be configured andsized to be compatible with the published Micro-USB cable and connectorstandards. In the illustrated example embodiment, connector 300 is aMicro-B USB connector and an optional raised letter “B” representativethereof may be provided on connector body 310, e.g., in recess 314thereof where it provides further indication of the orientation ofconnector body 310. The present arrangement is configurable to becompatible with mini-USB and micro-USB connectors, type A and type B USBconnectors, and with USB 1.x, 2.x and 3.x standards, as well as withother non-USB connectors, of both standard and proprietary types, andthe term “USB” is intended to include any and all of the foregoing USBconnector types, as well as future USB connector types.

FIG. 9 is an electrical schematic diagram of an example embodiment of anelectrical circuit 200 suitable for use with the example embodiment of abattery charger 100 of FIGS. 1-8, and FIG. 9A is an alternative exampleembodiment of the example electrical circuit of FIG. 9. Therein, chargerinput connectors 152, 154 for receiving electrical power from either ofthe two power supplies 168 are shown at the upper left and the two pairsof output charging contacts, identified as C+ and C− to indicate DCpolarity, for providing electrical charging power to the two receptaclesor cradles 110, 120 are shown at the far right.

A DC converter 210 including regulator integrated circuit U1 and itsassociated components shown in the left half of the schematic diagramprovide, e.g., a buck PWM (pulse width modulated) voltage regulator thatconverts the input voltage at connector 152 from the 12/18/24 VDCvoltage of power supply 168 (identified as VDD) down to about 5.1 VDC(nominally 5.12 VDC) at the cathode of D3, also designated as VDD, whichpowers the battery charging via output charging contacts C+ and C− whenthe 12/18/24 VDC power supply 168 is connected via connectors 152, 162and is electrically powered.

The +5 VDC provided via the USB connection 154 is directly connected asVDD to power the battery charging via output charging contacts C+ and C−when the charging power from power supply 168 is provided via the USBconnectors 154, 164. Because mechanical interference between connectors162 and 164 prevents both of connectors 162 and 164 from being mated tocharger port 150 at the same time, thereby to prevent electrical powerfrom being applied via both power supply input connectors 152, 154 atthe same time, no diode or other isolation thereof is needed to preventa connection being made between two external power supplies 168 throughthe circuitry of charger 100.

Microprocessor or microcontroller 220, U2 controls operation of thecharging circuitry 200 of charger 100. The type of power supply 168 thatis connected 152, 154 is detected by microprocessor U2 and predeterminedmaximum current levels that can be drawn from that type of power supply168 are then set accordingly. In the case of a USB power supply 168,signals on pins D− and D+ may be utilized to indicate the type of USBpower supply, e.g., a USB “cube,” and the maximum current that will bedrawn therefrom may be set accordingly to a predetermined level.

In the event that the +5 VDC voltage supplied by the USB power supply168 were to be below a predetermined minimum voltage, e.g., about 4.52volts (nominal value), the maximum current that will be drawn by charger100 may be and preferably is reduced by microprocessor 220, U2 inincrements of current until the number of increments of reduced currentis sufficient to reduce the maximum current drawn to a sufficientlylower current so that the voltage supplied by the USB-power source 168increases to a level greater than the predetermined minimum voltage,e.g., greater than about 4.52 volts, but not to reduce the current belowwhat is needed to provide some charging for a flashlight 180 and/orbattery 190, e.g., about 50 milliamperes. Preferably this featureoperates based only on the measured voltage received from a USB powersource 168 independently of the power rating and power dissipation ofthe USB power supply 168 which is need not be measured nor calculated,and preferably is not measured nor calculated.

Two independent linear charge current regulators 230, 240 are providedrespectively by FET transistors Q2 and Q4 under control ofmicroprocessor 220, U2 for providing respective predetermined constantcharging currents to a flashlight 180 in the first receptacle 110 and/orto a battery 190 in the second receptacle 120, i.e. at their respectivecharging contacts C+ and C−. Charging current may be supplied to bothsets of output charging contacts C+ and C− simultaneously or to one setof output charging contacts C+ and C− when only a flashlight 180 or abattery 190 is present in its respective receptacle 110, 120 or when thecharging current to one set of charging contacts is reduced, e.g., tozero, when the battery 190 (in flashlight 180 in cradle 110 or a battery190 in cradle 120) connected thereto is fully charged.

In each instance, the magnitude of the charging currents provided at therespective output charging contacts C+ and C− is determined andcontrolled by operation of microprocessor or microcontroller U2, 220 andits associated components shown in the right half of circuit 200 in theschematic diagram. FET Q6 may prevent discharge of a flashlight battery190 in the first cradle 110 and of a separate battery 190 in the secondcradle 120 from discharging into the charger circuitry 200 when inputpower from a power supply 168 is not present, e.g., when the powersupply 168 is disconnected. FETs Q2 and Q4 serve to prevent overchargeof the battery in the corresponding cradle 110, 120 due to conduction bythe inherent body diode of a FET.

A primary charge control circuit 230 for the primary cradle 110 includesresistor R11 for sensing the charging current flowing via Q2 and (upper)charging contacts C+ and C− (e.g., contacts 116, all at the upper rightof the diagram) into a battery 190 in a flashlight 180 connected betweenthose charging contacts C+ and C−, 116, wherein feedback from currentsensing resistor R11 is applied to the non-inverting (+) input of anoperational amplifier (e.g., upper triangular symbol) of microprocessorU2, 220, thereby to linearly control transistor Q2. If the feedbacksignal from resistor R11 exceeds the reference signal, then theconduction of FET Q2 is reduced to reduce the charging current and ifthe feedback signal is less than the reference signal, then theconduction of FET Q2 is increased to increase the charging current,thereby to supply a substantially constant current to battery 190.

The voltage of a battery 190 in a flashlight 180, e.g., the open circuitvoltage thereof, connected between those (upper) charging contacts C+and C− (116) is measured by microprocessor U2 via resistor divider R9and R10 when transistor Q3 is turned on.

The predetermined value of substantially constant charging current iscontrolled by controlling the “reference” level which is applied to theinverting (−) input of the upper operational amplifier via a low passfilter network including resistors R14, R15 and R16 and capacitor C6.The output from microprocessor U2, 220 to the lowpass filter may be ananalog signal or a digital signal, e.g., a PWM signal, and the output ofthe low-pass filter provides a filtered analog reference signal to theinverting (−) input of the upper operational amplifier of microprocessorU2, 220 to control the magnitude of the battery charging currentprovided to primary cradle 110.

A secondary charge control circuit 240 for the secondary cradle 120includes resistor R21 for sensing the charging current flowing via Q4and (lower) charging contacts C+ and C− (all at the lower right of thediagram) into a battery 190 connected between those charging contacts C+and C−, wherein feedback from current sensing resistor R21 is applied tothe non-inverting (+) input of an operational amplifier (e.g., lowertriangular symbol) of microprocessor U2, 220 thereby to linearly controltransistor Q4. If the feedback signal from resistor R21 exceeds thereference signal, then the conduction of FET Q4 is reduced to reduce thecharging current and if the feedback signal is less than the referencesignal, then the conduction of FET Q4 is increased to increase thecharging current, thereby to supply a substantially constant current tobattery 190. The secondary or “piggyback” charger 120 and its circuitry240 are an optional feature of charger 100, and are configured to beadded to and removed from housing 130 of charger 100.

The voltage of a battery 190 connected between those (lower) chargingcontacts C+ and C− is measured by microprocessor U2, 220 via resistordivider R19 and R20, when transistor Q5 is turned on.

The predetermined value of charging current is controlled by controllingthe “reference” level which is applied to the inverting (−) input of thelower operational amplifier via low pass filter network includingresistors R24, R25 and R26 and capacitor C7. The output frommicroprocessor U2, 220 to the lowpass filter may be an analog signal ora digital signal, e.g., a PWM signal, and the output of the low-passfilter provides a filtered analog reference signal to the inverting (−)input of the lower operational amplifier of microprocessor U2, 220 tocontrol the magnitude of the battery charging current provided to cradle120.

Each of the primary and secondary charging circuits 230, 240 operates inthe same manner, however, each provides a level of charging current to abattery in cradle 110 and 120, respectively, that is determinedindependently of the other based upon the terminal voltage, e.g., anopen-circuit terminal voltage, of the particular battery 190 it ischarging. The charging current may be reduced from those levels if thecurrent available from the external power supply 168 is insufficient tocharge both batteries 190 in both cradles 110, 120 at their respectivepredetermined substantially constant current levels at the same time.

Because during charging there is a significant voltage differencebetween the voltage at charging contacts C+ and C− and the terminalvoltage of the battery (cells) 190 of the flashlight 180 or of batterypack 190 being charged, e.g., due to contact resistance (e.g., betweencontacts 116 and 189) and wiring resistance and/or due to serieselements within the flashlight 180 or battery pack 190, e.g., a diode inparallel with a resistor, the battery terminal voltage cannot bemeasured with sufficient accuracy at charging contacts C+ and C− whenthe battery 190 is being charged. Therefore, charging is interruptedperiodically (e.g., charge current is essentially zero) so that thebattery 190 open circuit voltage may be measured.

Each charging circuit 230, 240 operates on a predetermined repeatingcycle wherein charging current is provided for a very large portion ofthe cycle, and is interrupted for a much shorter time during which theopen circuit voltage of battery 190 is measured and a predeterminedlevel of charging current, e.g., a substantially constant chargingcurrent, is set for the next period of charging based upon the measuredopen circuit battery voltage. In one example embodiment in which eachcycle of charging is about 2.10 seconds in duration, charging isinterrupted for about 25 milliseconds, e.g., about 1% of the cycle,during which the open circuit voltage of the battery is measuredfollowed by an about 2.07 second charging time, e.g., about 99% of thecycle, at the current determined by the open circuit voltage measuredimmediately prior thereto. The cycling of the respective chargingcircuit cycles of circuits 230, 240 for electronic device cradle 110 andbattery cradle 120 could be concurrent, i.e. in unison, or theirrespective repeating cycles could be offset from each other in time,e.g., by about half the cycle time, e.g., by about 1.05 seconds in theexample cycle.

An example of typical values of battery open circuit voltage Voc andcorresponding typical charging current levels for an example Lithium-Ionbattery is presented in Table I following:

TABLE I BATTERY CHARGE CURRENT & BATTERY VOLTAGE (4) If Battery V_(OC)Is: Then I_(CHARGE) Should be: Notes: <4.0 VDC 750 milliamperes (1),(2) >4.0 VDC 500 milliamperes (1) >4.1 VDC 200 milliamperes (1) >4.2 VDC 0 milliamperes (1), (3) Notes: (1) If temperature is within limits forcharging. (2) May begin charging gently if battery state of charge isvery low or temperature is too high or too low. (3) Lithium batterycharging is cut off; other battery types may be trickle charged. (4)Values are examples and will be different for different batteries, e.g.,batteries of different capacity and/or from different manufacturers.

A thermistor, e.g., thermistor TR1, may be provided in the case orhousing 132 of the charger base 130 to sense the ambient temperaturethereof; the thermistor TR1 is not attached to a power transistor or toa power supply or to a heat sink for measuring the temperature or powerdissipation thereof. Thermistor TR1 and resistor R18 form a voltagedivider that supplies a temperature dependent voltage signal tomicroprocessor U2, 220 from which microprocessor U2, 220 preferablydetermines the ambient temperature of charger 100, e.g., for the purposeof controlling the charging current applied to a battery being chargedin cradle 110 and/or 120 responsive to ambient temperature. ThermistorTR1 is preferably used to prevent a battery 190 from (a) being chargedif the battery is too “hot” (e.g., above 122° F.) or being charged at ahigh charge current if the battery is “cold” (e.g., below 20° F.), asapproximated by the likelihood that the ambient temperature of thecharger base 130 is indicative of the temperature of the battery 190 orwould be after a period of time. It is noted that the temperaturesreferred to as “hot” and “cold” may differ for different embodiments anddifferent sizes and types of batteries.

Charger 100 preferably applies charging current only at predeterminedfixed levels to charge a battery and need not control, and preferablydoes not control, the voltage applied to the battery or apply a fixed orpredetermined voltage thereto, i.e. it does not provide, and preferablydoes not provide, a constant voltage to the battery. Preferably, datastored, e.g., in microprocessor 220, U2 or in a memory associatedtherewith, defines predetermined substantially constant current levelsfor charging current to be applied to charge battery 190 as a functionof open circuit battery voltage, and charger 100 preferably does notneed and does not have a table of values that relate a voltage to beapplied to the battery 190 to the battery open circuit voltage and/or toan “optimum” battery voltage, and so does not need to and preferablydoes not measure the voltage applied to battery 190 while battery 190 isreceiving charging current. Charger 100 need not and preferably does notmeasure or calculate the power dissipation of any power supply 168 andneed not and preferably does not measure or calculate the powerdissipation of any power transistor. Electrical circuit 200′ of FIG. 9Ais substantially the same as electrical circuit 200 of FIG. 9 withcertain changes thereto. For example, plural transient voltagesuppression devices TVS are included with TVS1 connected across resistorR4, TVS2 connected across capacitor C4, TVS3 connected across resistorR6, TVS4 connected across indicator LED2, TVS5 connected acrossindicator LED1 which is reconfigured relative to its drive fromprocessor 220, TVS6 is connected between the C+ and C− terminals 116 ofcradle 110, and TVS7 is connected between the C+ and C− terminals ofcradle 120. In addition, capacitor C9 is connected across thegate-source terminals of FET Q2 and capacitor C10 is connected acrossthe gate-source terminals of FET Q4. Resistor R28 also assists insuppressing transients.

Each charging circuit 230, 240 of circuit 200 and of circuit 200′preferably operates on a predetermined repeating cycle wherein chargingcurrent is provided for a very large portion of the cycle, and isinterrupted for a much shorter time during which the open circuitvoltage of battery 190 is measured and a predetermined level of chargingcurrent, e.g., a substantially constant charging current, is set for thenext period of charging based upon the measured open circuit batteryvoltage. In one example embodiment, each cycle of charging is about 2.10seconds in duration and charging is interrupted for about 25milliseconds, e.g., about 1% of the cycle, during which the open circuitvoltage Voc of the battery is measured followed by an about 2.07 secondcharging time, e.g., about 99% of the cycle, at the constant currentdetermined by processor 220 based upon the open circuit voltage Vocmeasured immediately prior thereto.

While the cycling of the respective charging circuit cycles of circuits230, 240 for electronic device cradle 110 and battery cradle 120 couldbe concurrent, i.e. in unison, or their respective repeating cyclescould be offset from each other in time, e.g., by about half the cycletime, e.g., by about one second in the example cycles described.Preferably, batteries in both cradles are charged concurrently withpriority being given to the battery in cradle 110, which is thought tobe more likely to be quickly put back into use, although alternativecharging priority may be provided, e.g., preferentially charge thebattery in cradle 120, or share the available charging relatively evenlybetween the batteries in cradle 110 and in cradle 120.

An example of typical values of battery open circuit voltage Voc andcorresponding typical charging current levels for an example Lithium-Ionbattery is presented in Table II following:

TABLE II BATTERY CHARGE CURRENT & BATTERY VOLTAGE (4) If Battery V_(OC)Is: Then I_(CHARGE) Should be: Notes:  <4.2 VDC 750 milliamperes (1),(2) then:  0 milliamperes for time T_(D)  <4.2 VDC 100 milliamperes (1) ≥4.2 VDC  0 milliamperes (3) <4.05 VDC If Voc decreases, repeat cycleNotes: (1) If temperature is within limits for charging, e.g., 50° F. to101° F.. (2) May begin charging gently if battery state of charge isvery low, e.g., V_(OC) is low, or temperature is either too high or toolow, e.g., at a temperature less than about 40° F. or higher than about100° F. (3) Lithium battery charging is cut off; other battery types maybe trickle charged. (4) Values are examples and will be different fordifferent batteries, e.g., batteries of different capacity, differentchemistry, and/or from different manufacturers, and/or at differenttemperatures (above about 113° F. the charging cut off voltage is about4.1 VDC).

Because it is desirable to charge or recharge the battery in theshortest time allowable, a constant charging current that is close to amaximum allowable safe charging current may be applied, and so theterminal voltage of the battery being so charged may increase slightlyabove the voltage representative of being fully charged. When thebattery is rapidly charged, e.g., at 500 milliamperes or at 750milliamperes, its terminal voltage Voc changes and so a “relaxation”time TD may be provided before charging is resumed, e.g., before toppingoff the charge. The time TD may be a predetermined time, e.g., about 4minutes or longer, and in a typical example about 4.25 minutes, or maybe a function of a predetermined parameter, e.g., of a temperature or acurrent at which charging was done, which may be measured within charger100, or may be related to the temperature of the battery being charged.The foregoing does not require that battery temperature or any otherparameter be monitored or compensated for, however, it does not precludesuch monitoring and/or compensating of temperature or another parameter.

Optionally, but preferably, charger 100 detects which of the possibleexternal charging sources 168 is connected to and supplying chargingcurrent to charger 100. External charging power source 168 may be a12-18 volt or a 12-24 volt source such as may be provided from typicalAC power mains or from a vehicle power system, such as battery chargerpower sources supplied by Streamlight, Inc. of Eagleville, Pa., forvarious wall and vehicle mountable chargers, or external charging powersource 168 may be a USB compatible power source. With such powersources, charging currents of about 750 milliamperes may provided to onebattery and/or about 1000 milliamperes (about one ampere) total may beprovided to both batteries (both cradles 110, 120).

When charging power is provided from a detected USB external powersource, e.g., a laptop computer or smart phone or a typical USB powercube, the maximum current that can be drawn therefrom is limited, e.g.,to about 500 milliamperes. In that instance, where only a single batteryis present to be charged, e.g., a battery only in cradle 110 or abattery only in cradle 120, but not in both, will be charged using thefull available current, e.g., about 500 milliamperes, available from theUSB external source 168; however, if a battery is also in cradle 120,e.g., there are batteries in both of cradles 110 and 120, then themaximum charging current to the battery in cradle 110 is reduced, e.g.,to about 400 milliamperes, and the remainder, e.g., about 100milliamperes, will be utilized to charge the battery in cradle 120,although other apportionments of the available charging current may beutilized.

If, however, the external USB power source 168 is a Streamlight AC/5VUSB power cube adapter that will be made available with the charger 100described herein, the maximum available current that can be drawn isabout 1 ampere (about 1000 milliamperes). Preferably, the StreamlightAC/5V USB power cube adapter has the data+ and data− terminals of itsUSB connector connected together by a very low resistance, e.g., zeroohms, thereby making its presence easily detectable by processor 220 ofcircuit 200, 200′ of charger 100. Thus, if the battery in cradle 110 isbeing charged at a constant current of about 750 milliamperes, theremaining about 250 milliamperes of available current may be utilized tocharge a battery in cradle 120, assuming that temperature and batteryopen circuit voltage Voc are within the limits permitting such highcurrent charging, thereby giving priority to the battery in cradle 110as is preferred in the present example.

Indicator lights LED1 and LED2 relating to cradles 110 and 120,respectively, may be, and preferably are, each energized in differentmanners so as to convey information about the charging of the battery ineach respective cradle 110, 120. For example, the LED indicator may bepulsed, e.g., at once per second, to indicate that the battery beingcharged is substantially at or near full charge and is in thepredetermined time period TD, and the LED indicator may be blinked onand off at a fast rate, e.g., easily observable as being faster thanonce per second, to indicate an error, e.g., when charging has ceaseddue to too high or too low a temperature.

When the temperature is either high or low, e.g., less than about 41°F., charge current preferably is limited, e.g., to about 200milliamperes, and when temperature is less than about 50° F. or higherthan about 101° F., charge current preferably may be limited, e.g., toabout 490 milliamperes; no charging will be done at temperatures thatare too high or too low, e.g., below about 20° F. and above about 122°F. At a temperature above about 113° F., the charging terminationvoltage is reduced, e.g., from about 4.2 VDC to about 4.1 VDC.

FIGS. 10 and 10A are schematic flow diagrams illustrating an example ofthe operation 1100 of the example embodiment of a battery charger 100and electrical circuit 200 of FIGS. 1-9A. In general, FIG. 10 is anoverall flow diagram presented to describe the major functions 1100 ofbattery charger 100 in a general manner with the following FIG. 10Aproviding further details and/or alternatives for the major functions1100 of FIG. 10. It is noted that the functions may be performed in asequence different from the example sequence illustrated unlessspecifically stated that a particular order or sequence must befollowed. It is further noted that some functions described may beremoved and/or other functions may be added, as may be expeditious inany particular instance.

Operation or process 1100 is first initialized 1110 upon application ofelectrical power to the charger 100 so that its operation commences froma known predetermined condition, and then checks 1300 to see if abattery is present, e.g., to detect 1300 if a battery 190 (e.g., in aflashlight 180) is connected in cradle 110 (battery #1), or if a battery190 is connected in cradle 120 (battery #2), or both cradles 110 and120.

At some point in process 1100 after a battery is detected 1300, process1200 commences to detect and identify 1200 the type of power supply 168that is connected to charger 100 and supplying electrical power thereto.Based upon the type of power supply detected, e.g., upon the level ofcurrent that is know to be available from such type of power supply, amaximum current level Imax is established (set) 1250. Process 1200 maybe performed at any one of several times, e.g., after a battery isdetected 1300 or after charging current is initialized 1400, wherein thelatter is currently thought to be preferred.

If the identified power supply 168 is a 12/18/24 VDC power supply 168connected via connector 152, then the known level of current that can bedrawn therefrom may be relatively high, e.g., 1.8-2.5 amperes, however,if the identified power supply 168 is a USB power supply 168 connectedvia connector 154, then the current that can be drawn may vary over awide range, e.g., 100 milliamperes to 2.4 amperes, depending upon thenature of the source. Power drawn from the USB port of an electronicdevice, e.g., a portable computer, may be limited to a low value, e.g.,100 milliamperes, while up to 2.4 amperes may be drawn for a USB wallcube that plugs into a 110-240 VAC wall outlet.

Thereafter, process 1100 proceeds to initialize 1400 the chargingcurrent that is applied to battery #1 and/or battery #2, as may beendetected 1300. Charge current initialization 1400 is illustrated asseparate functions 1400-1 and 1400-2 because the current level must beset for each of the current controlled constant current chargingcircuits 230, 240, however, the value to which the charging currents areinitially set 1400 may be established by the initialization 1110 ofprocess 100. Typically, and preferably, the initial charging current isinitially set 1400 to a relatively low value at which it is safe tocharge a battery irrespective of temperature and the battery's state ofcharge, which might be thought of as a safe charging mode.

While the initial charging 1400 usually, and preferably, is the same forboth battery cradles 110, 120, subsequent charging 1500 for eachbattery, labeled as 1500-1, 1500-2 is likely to be at different currentlevels depending upon the respective states of charge of the twobatteries when batteries are present in both cradles 110, 120, and uponthe sequence in which charger 100 is programmed to charge batteries180-190 and 190 when batteries are present in both cradles 110, 120.Thus, due to similarity, only one of each of the charging regimes 1400,1500 need be described.

As to the sequencing, e.g., priority of charging, for the battery 190 ofa flashlight 180 in cradle 110 and for a battery 190 in cradle 120, inone preferred embodiment the charging of flashlight 180 is givenpreference because it is thought that if both a flashlight 180 and aspare battery 190 are present 1300 in battery charger 100, then it isprobably more likely that a user will first remove flashlight 180 foruse (desiring that it be substantially if not fully charged) beforeremoving a spare battery 190 for use. In any event, it is preferred thatif a flashlight 180 is present 1300, but not a battery 190, or if abattery 190 is present 1300, but not a flashlight 180, then whicheverone is present is given charging priority, at least for as long as it isthe only one present in charger 100.

Alternatively, the one of flashlight 180 and battery 190 that is closestto being fully charged, e.g., as determined from its open circuitvoltage, could be given priority in charging, or an extra battery 190could be given priority over a flashlight 180, or both could be giventhe same priority. When both are given the same priority, charging bothsimultaneously at a reduced charge current level or charging bothcontemporaneously at a relatively higher current level on alternatingrepetitions of the relatively short about 2 second charging time of therepeating cycles described herein typically might lengthen the timenecessary for either or both to reach full charge.

Returning to operation 1100, each battery is charged under the samecharging process 1500 although the particular levels of current appliedat any time will be separately determined based upon the parameters ofeach particular battery, e.g., as determined by its open circuitvoltage. Each process 1500 (1500-1, 1500-2) begins by counting time todetermine 1515 whether the predetermined charging time has been reached.If not 1515N, it continues counting time 1515. When the predeterminedcycle time, e.g., 2 seconds, has been reached 1515Y, charging isinterrupted 1520 for a short interval sufficient to measure 1525 theopen circuit voltage Voc of the battery which is then receiving nocharging current. Therein, measuring 1525 Voc also includes determining1530 whether a battery is still present and if not 1530N, returning tobattery detection process 1300. If a battery is present 1530Y, then thecharging 1535-1580 of that battery commences and/or continues.

Charging 1500 includes repetitively measuring the open circuit batteryvoltage Voc in each repeating cycle and setting a level of chargecurrent for the next cycle that is determined 1535-1580 based upon themeasured open circuit battery voltage Voc of the battery immediatelypreceding that cycle. Recall that the charging current was initially setto a relatively low level that is deemed to be safe. If Voc isdetermined 1535 to not be greater than a voltage Vsafe which is aminimum battery voltage at which charging at a relatively high currentis safe, then 1535N returns to process 1400 where the battery is chargedat the safe relatively low current.

If Voc is determined 1535 to be greater than a relatively low voltageVsafe indicating that charging of the battery can begin in earnest, then1535Y is followed and if the measured battery voltage Voc is determined1540 to be less than a first predetermined voltage, then 1540N isfollowed and the charging current is set 1545 to a relatively high valueIchg=Imax/N, wherein Imax/N is the lower of the maximum current that cansafely be applied to charge the battery 180, 190 and the maximum currentthat may be drawn from power supply 168 divided by the number N ofbatteries to be charged simultaneously or contemporaneously. Havingestablished (set) 1545 the predetermined level of charging current to beapplied, charging resumes 1550 applying that predetermined level ofcharging current to the battery for the present repetitive chargingcycle.

Thus begins a series of determinations 1540, 1560, 1570, . . . 1580wherein the last measured 1525 battery voltage Voc is compared to a setof different predetermined voltages to determine 1540, 1560, 1570, . . .1580 the level of charging current that is to be applied 1550 to chargethe battery for the immediately following charging interval. Dependingupon the last measured 1525 value of battery open circuit voltage Voc, apredetermined level of charge current is selected (set) 1545, 1565,1575, . . . 1585 and is applied 1550 to charge the battery for theimmediately following charging interval.

The determinations 1540, 1560, 1570, . . . 1580 occur by following the Ypaths from each until a negative determination 1540, 1560, 1570, . . .1580 is made and the N path from that comparison 1540, 1560, 1570, . . .1580 is followed to set 1545, 1565, 1575, . . . 1585 the charge currentlevel. In this description and the Figures to which it relates, anellipses (“ . . . ”) is used to indicate that a greater or lesser numberof steps, e.g., comparisons 1540, 1560, 1570, . . . 1580 and currentsettings 1545, 1565, 1575, . . . 1585, could be employed.

If all of comparisons 1540, 1560, 1570, . . . 1580 are negative, one oftheir possible N paths is followed, and battery charging continues 1550at the last set 1545, 1565, 1575, . . . 1585 level of charging current.If the battery open circuit voltage Voc is determined 1580 to be equalto or greater than a predetermined voltage Vfc that is indicative thatthe battery is fully charged, then 1580Y is followed and the charging isterminated 1590, i.e. the charging current is set 1590 to zero current.

At this point, the charging cycling 1500 continues to repeat at thepredetermined repetitive cycle time, e.g., at the about 2.1 seconds. Ifthe flashlight 180 and/or battery 180, as the case may be, continues topresent an open circuit voltage Voc that equals or exceeds the fullcharge voltage Vfc, charging current remains set 1585 at zero, andshould the open circuit voltage Voc decrease to below the full chargevoltage Vfc, charging current will be set 1545, 1565, 1575, . . . 1585in accordance with the then presented open circuit voltage Voc.

The foregoing processes 1400, 1500 repeat until one or both of theflashlight 180 and/or battery 190 are removed from the respective cradle110, 120 of battery charger 100 whereat the affected charging cycle1400, 1500 return to detection 1300 and the unaffected charging cycle1400, 1500 continues as described.

FIGS. 11A, 11B and 11C are together a single schematic flow diagramillustrating an example of an alternative operation 2000 of the exampleembodiment of a battery charger 100 and electrical circuit 200 of FIGS.1-9A. It is noted that the functions of operation 2000 or process 2000may be performed in a sequence different from the example sequenceillustrated unless specifically stated that a particular order orsequence must be followed. It is further noted that some functionsdescribed may be removed and/or other functions may be added, as may beexpeditious in any particular instance. Process 2000 begins with theinitialization 2005 of the charger electronic circuitry 200 so thatprocess 2000 commences from a known state, e.g., upon initially beingpowered on and after a power interruption or outage.

It is noted that process 2000 repeats periodically so that the status ofcharger 100, the charging of battery #1 in cradle 110, the charging ofbattery #2 in cradle 120, the parameters thereof established for safecharging and or other safety and other reasons, are all repetitivelymonitored and adjusted so the batteries #1 and #2 may be rapidly andefficiently charged under whatever conditions are detected. Typically,process 2000 is repeated many times during each cycle of batterycharging and voltage Voc measuring, e.g., 32 times per each cycle of 1.1or 2.1 seconds in the examples herein.

First, the presence of a rail voltage is checked 2010, 2015 to beginverifying that input power is being received 2010 from an externalsource 168 of charging power and whether the rail voltage is within apredetermined acceptable range of voltages 2015, e.g., either by testing2015 whether it is outside of that range (as illustrated) or whether itis within that range. If the rail voltage Vrail is outside thepredetermined range, then 2015—Y (“Y” indicates “yes” and “N” indicates“no”) is followed and a Verror count is incremented 2020 or a Verrorflag is set 2020 thereby to indicate an out of range condition. If therail voltage Vrail is within the predetermined range, then 2015—N isfollowed and the Verror flag or count is cleared 2025 thereby toindicate an in-range value of the Vrail input voltage.

The Vrail error flag or count is tested 2030 and if the error flag orcount is set, then 2030—Y is followed directly to step 2060. If theVerror flag or count is not set, then 2030—N is followed and thetemperature is checked 2040 to determine, e.g., whether it is safe tocharge the battery and if so, at what constant current level.Temperature is checked 2040, 2045 to begin verifying whether thetemperature is within a predetermined acceptable range of temperature2045, e.g., either by testing 2045 whether it is outside of that range(as illustrated) or whether it is within that range. If the temperatureis outside the predetermined range, then 2045—Y is followed and a Terrorcount is incremented 2050 or a Terror flag is set 2050 thereby toindicate an out of range condition. If the temperature is within thepredetermined range, then 2045—N is followed and the Terror flag orcount is cleared 2055 thereby to indicate an in-range or acceptabletemperature.

If a Verror or Terror flag is set 2060, then battery charging should notbe commenced or continued and 2060—Y is followed to stop charging 2065and to blink an indicator light 2065, e.g., if a battery is detected asbeing present in a cradle 110, 120, and to return to step 2010. If aVerror or Terror flag is not set 2060, then battery charging should becommenced or continued and 2060—N is followed to determine 2070 themaximum level of constant current charging allowable and the chargecompletion voltage Voc based upon the last determined temperature 2040.

If a battery #1 flag is set 2075, e.g., a battery has been detected asbeing present in cradle 110, 2075—Y is followed to go to step 2150.Detection of the presence of a battery may employ any one of severaltests, e.g., signaling the charge current circuit 230 or 240 to apply ashort duration pulse of charging current while monitoring the chargingcurrent feedback, e.g., via resistor R11 or R21, to determine whethersuch current actually flows because current will only flow if a batteryis connected to terminals 116 of cradle 110 or to those of cradle 120.

If a battery #1 flag is not set 2075, e.g., a battery was not detectedas being present in cradle 110, 2075—N is followed to indicate 2080 thatthe battery is not charging and to check 2080 the battery voltage Voc.If the battery voltage Voc indicates 2085 that charging is complete,then 2085—Y is followed and the battery detected and charge completecounts are incremented 2090 and process 2000 proceeds to 2110. If thebattery voltage Voc indicates 2085 that charging is not complete, e.g.,the battery is not fully charged, then 2085—N is followed and the chargecomplete count is cleared 2095, a pulse of charging current is applied2095 and the battery detected count is incremented 2095.

If the charging current is regulating to a constant current 2100, then abattery is present and being charged and 2100—Y is followed to 2110. Ifthe charging current is not regulating 2100, then 2100—N is followed toclear 2105 the battery detected count. If the detected count is not ator above a predetermined count 2110, e.g., the detect count is not greatenough 2110, then 2110—N is followed to step 2150. If the detected countis at or above a predetermined count 2110, e.g., the detect count isgreat enough 2110, then 2110—Y is followed to determine 2115 if thecomplete count is enough. If the complete count is enough 2115, then2115—Y is followed, the charge complete flag is set 2120, and process2000 proceeds to step 2125. If the complete count is not enough 2115,then the battery should continue charging and so 2115—N is followed, thedetect flag is set 2125, the charging indicator light is energized toindicate 2125 that the battery is charging, and process 2000 proceeds tostep 2150. Thus far in example process 2000, at least the initialsetting up of the charging of a battery in cradle 110 for which chargingpriority is desired to be given is established.

Step 2150 determines whether charger 100 is in a “piggyback”configuration, e.g., whether or not an auxiliary cradle 120 is presentin addition to the primary cradle 110 included in housing 110. If anauxiliary cradle 120 is not present, then 2150—N is followed to proceedto step 2210. If auxiliary cradle 120 is present, then 2150—Y isfollowed to determine 2155 whether a battery is present in cradle 120,e.g., as indicated by a battery #2 detected flag being set 2155. If yes,then 2155—Y is followed to proceed to step 2210. If a battery is notdetected 2155 in cradle 120, then 2155—N is followed to step 2160.

Steps 2155 through 2205 relating to battery #2, e.g., the battery incradle 120, are exactly parallel to and substantially the same as steps2075 through 2125, and so will not be separately described herein. Steps2155 through 2205 are described by the description of steps 2075 through2125 if 80 is added to the item numbers set forth in the description ofsteps 2075 through 2125, respectively.

If neither battery flag is set 2210, then no battery is present and2210—N is followed to step 2215 to set an input source flag to “0” toforce a redetermination of the charging current level at step 2300. Step2215 proceeds to step 2010. If either battery flag is set, then 2210—Yproceeds to step 2220 to control the charging of battery #1, e.g., thebattery in cradle 110.

Control of the charging of battery #1 proceeds as follows: First,completeness of charging is determined 2220, e.g., by testing thebattery voltage Voc against a predetermined charging terminationvoltage, e.g., 4.2 VDC. Steps 2220-2235 can check whether the battery iscurrently being “topped off,” because after charging is complete, thebattery could be in the relaxation time, in topping off, or hascompleted topping off after which the battery voltage is monitored todetermine whether the battery voltage Voc has dropped below apredetermined threshold voltage, e.g., 4.05 VDC, indicating thatcharging should be resumed or the battery has been removed. If thecharging of battery #1 is not complete 2220, then 2220—N is followed tostep 2245 for beginning a parallel and substantially the same chargingcontrol process for battery #2. If the charging of battery #1 iscomplete 2220, then 2220—Y is followed to step 2225 for energizing thecharging indicator light to indicate that charging of battery #1 incradle 110 is complete, e.g., flashing at a once per second rate. Ifcomplete, the battery voltage Voc is monitored 2230 to determine if“topping off” the charge 2230 is being performed. Topping off is doneafter a period of time commencing at the indication of completion ofcharging and ending at a later time, e.g., either based upon apredetermined time, by a temperature, or by a combination thereof.Topping off may comprise charging at a lower constant current, e.g., atabout 100 milliamperes. If topping off 2230 is yes, then 2230—Y isfollowed to step 2245. If topping off 2230 is no, then 2230—N isfollowed to determine 2235 whether the battery voltage Voc is less thanthe voltage indicating that restarting charging should occur, e.g., thecharge restart voltage of about 4.05 VDC. If it is not, then 2235—N isfollowed to step 2245. If it is, then 2235—Y is followed to increment2240 the undetected count and set 2240 an undetected flag, and proceedto step 2245.

Steps 2245 through 2265 relating to battery #2, e.g., the battery incradle 120, are exactly parallel to and substantially the same as steps2220 through 2240 and so will not be separately described herein. Steps2245 through 2265 are described by the description of steps 2220 through2240 if 25 is added to the item numbers set forth in the description ofsteps 2220 through 2240, respectively. The completion of steps 2245-2265and of steps 2220-2240 both lead the process 2000 to step 2300. Steps2245—N, 2255—Y, 2260—N, and 2265 lead the process 2000 to step 2300.

Step 2300 determines 2300 whether the input source flag is determinedyet, e.g., what type of source is present. If zero, then the type ofsource is not determined and 2300—Y is followed to determine the source2305 that is present, e.g., the type of external source of chargingpower 168 that is connected, e.g., a Streamlight USB source beingindicated by a very low or zero resistance between its data+ and data−terminals, and to set 2305 the maximum current that will be drawn fromthat source. Once the type of source 168 is determined, the value of theinput source flag is set to a value corresponding to the current levelthat is available from the determined type of source. If the inputsource 168 is already determined, then 2300—N is followed to step 2310as also follows step 2305.

Charging status for battery #1 is determined 2310. If battery #1 ispresent and if the predetermined charging time between battery voltagemeasurements has been fulfilled and if battery #1 is charging, then2310—Y is followed to measure 2315 the battery open circuit voltage Voc.This step 2315 includes interrupting 2315 the charging current tobattery #1 and measuring the open circuit voltage Voc at the chargerterminals 116, checking (verifying) 2315 that battery #1 is stillpresent in cradle 110, reducing 2315 the maximum allowable batterycharging current setting if the voltage Voc of battery #1 is below apredetermined threshold considered to indicate that battery issubstantially discharged, e.g., “dead,” and resuming 2315 constantcurrent charging of battery #1 if the charging thereof is not complete,e.g., as indicated by its open circuit voltage Voc being below thecharge termination voltage. If test 2310 is negative, then 2310—N isfollowed to step 2320. At the completion of step 2315 which follows fromstep 2310—Y, the process 2000 proceeds to step 2350.

Charging status for battery #2 is determined 2320. Steps 2320 and 2325are parallel to and substantially the same as steps 2310 and 2315 forbattery #1 and will not be separately described, except to state thatsteps 2320-2325 pertain to battery #2, e.g., a battery in cradle 120.Step 2325 also leads to step 2350, as do steps 2310-2315, and step2320—N goes to step 2330. Step 2320—N goes to step 2330. At thecompletion of step 2325 which follows from step 2320—Y, the process 2000proceeds to step 2350.

Charging of battery #1 is resumed 2330-2335. If battery #1 is detected2330 and its charging is not complete, then 2330—Y is followed to resumecharging 2335 of battery #1. Resuming charging 2335 includes measuring2335 the constant current charging current, checking 2335 that battery#1 is still present, setting 2335 a target value for the constantcurrent charging of battery #1 based upon, e.g., temperature, its stateof charge, e.g., as indicated by its voltage Voc, and the type of inputsource present, e.g., the type of external charging current power source168, and reducing 2335 the charging current if it is above the newly settarget value. If test 2330 is negative, then 2330—N is followed to step2340 and at the completion of step 2335 the process 2000 also proceedsto step 2340.

Charging of battery #2 is resumed 2340-2345. Steps 2340 and 2345 areparallel to and substantially the same as steps 2330 and 2335 forbattery #1 and will not be separately described, except to state thatsteps 2340-2345 pertain to battery #2, e.g., a battery in cradle 120.Both lead to step 2350, and preferably after the constant chargingcurrents for batteries #1 and #2 have been set and applied.

The particular external charging current power source 168 that isconnected to charger 100, from which the electrical power from which theconstant currents that charge batteries #1 and #2 are drawn, is testedto determine 2350 whether it has sufficient capacity to supply thosecharging currents. Testing step 2350 is preferably performed bymeasuring the input voltage to charger 100, e.g., at input connectors152 or 154, but particularly at input connector 154 to which a USB powersource 168 can be connected. The external power source 168 provided byStreamlight, Inc. with the portable light described herein, as well aswith previous lights, can typically provide electrical power that ismore than sufficient to charge the light described herein.

USB power sources 168, e.g., USB power cubes (other than the StreamlightAC/5V USB adapter), typically have a much more limited capacity toprovide charging power at +5 VDC to charger 100, e.g., many provide onlyabout 500 milliamperes at +5 VDC, and so when current beyond thatcapacity is drawn, the voltage at connector 154 tends to decrease, orexperience “droop,” to a lower voltage. If the detected 2350 voltage“droops” below a predetermined voltage, e.g., about 4.52 volts, then2350—Y is followed and the battery charging currents are reduced 2355.For example, the maximum charging current to battery #1 will be reduced2355, e.g., in increments from as much as about 750 milliamperes, to alower level so that the total charging current to batteries #1 and #2 issimilarly reduced, thereby reducing the current drawn from externalpower source 168. In a preferred arrangement wherein the charging of thebattery #1 in cradle 110 is given priority regarding charging, thecharging current to battery #2 is reduced, thereby to reduce the currentdrawn from external power source 168, before the charging current tobattery #1 is reduced.

Reducing the current drawn from external power source 168 allows thevoltage provided thereby to recover, e.g., to droop less, until thevoltage from external power source 168 returns to an acceptable level,e.g., above about 4.52 volts. In a preferred example, the chargingcurrents to battery #1 and to battery #2 are both reduced 2355sufficiently for the voltage provided by external power source 168 torecover. Process 2000 then returns to step 2010 and begins another inits sequence of repetitive cycles. An advantage of the foregoingarrangement is that the current draw is automatically reduced to a levelthat does not draw excessive current from the external power source 168without having to know a priori or determine the actual currentsupplying capacity of source 168, which is seen to increase flexibilityto operate charger 100 with a wide variety of different capacity USBpower sources.

It is noted that voltage droop is not expected when the external source168 is one of the 12, 18 or 24 VDC sources which is configured toprovide sufficient power for charging such portable lights 110 with themaximum charge currents as described herein. Likewise, voltage droop isnot expected when external source 168 is the Streamlight AC/5V USB cubewhich is also configured to supply sufficient power to charge thebattery or batteries as the maximum charge currents described. However,for other USB power sources, e.g., a USB connector of a laptop computeror a smart phone charger, if the source is unable to supply the nominal500 milliampere that the charger is programmed to draw, then the voltageprovided by the USB source 168 will droop and the charging current willbe reduced. Because in the example described, charging of the battery incradle 110 is presumed to be given priority in charging, then anycharging current being provided to a battery in auxiliary cradle 120will be reduced before the charging current to the battery in cradle 110will be reduced. If the charging current to cradle 120 has already beenreduced to a predetermined minimum charging current, e.g., about 75milliamperes, and voltage droop is still detected, then the chargingcurrent to cradle 110 will be reduced in increments towards a minimumnominal value, e.g., about 100 milliamperes. The 400 milliamperecharging current example above for cradle 110 with a 100 milliamperecharging current for cradle 120 is just an example, e.g., at the end ofor in a sequence of incremental reductions controlled by process 2000.This preferred arrangement, may be varied, e.g., as different priorityfor charging may be desired as between the batteries in cradles 110 and120.

If the source 168 voltage is not droopy 2350, then 2350—N is followedand the charging currents to batteries #1 and #2 is incremented 2360upward over a number of repetitive cycles of process 2000 until thetarget current (see 2335, 2345) is reached. Process 2000 then returns tostep 2010 and begins another in its sequence of repetitive cycles.

In a typical embodiment, housings 130 and 140, and parts thereof such asspring arms 112, may be of any suitable metal, e.g., a cast, machined orstamped aluminum, or a suitable plastic material, e.g., preferably amolded plastic such as a nylon, engineered nylon, ABS plastic,polycarbonate, polyethylene, or other resin, with or without areinforcing material such as a fiberglass, carbon fiber, or the like, orany other suitable plastic or other moldable material. Reinforcingmaterials may provide improved strength, impact resistance, dimensionalstability and/or consistency, high temperature stability, and the like.

A battery charger 100 may comprise: a housing 110 having at least onecradle 110, 120 including electrical contacts for receiving arechargeable battery 180, 190; a connector port 150 on the housing 130for receiving at different times at least two electrical plug connectors162, 164, 300 having different electrical contact configurations; firstand second electrical receptacles 152, 162 disposed in the connectorport 150 of the housing 130 for receiving at different times respectivefirst and second electrical plug connectors 162, 164, 300 that arerespectively associated with first and second electrical power supplies168; the first electrical receptacle 152, 154 having a contactconfiguration that may be different from the contact configuration ofthe second electrical receptacle 154, 152; the first and secondelectrical receptacles 152, 154 being closely adjacent each other suchthat an electrical plug connector 152, 154 inserted into one of thefirst and second electrical receptacles 152, 154 physically interfereswith and prevents an electrical plug connector 154, 152 from beingplugged into the other of the first and second electrical receptacles152, 154; and an electrical circuit 200 disposed in the housing forcoupling electrical power received at the first and second electricalreceptacles 152, 154 to the electrical contacts of the at least onecradle 110. 120 of the housing. The connector port 150 may define anopening that includes a substantial part of an outline of a firstelectrical plug connector 162, 164 and a substantial part of an outlineof a second electrical plug connector 164, 162, wherein parts of theoutlines of the first and second electrical plug connectors 162, 164overlap within the opening of the connector port 150. One of the firstand second electrical receptacles 152, 154 may include a USB connector.The at least one cradle 110, 120 of the housing 130 may include: a pairof spring biased arms 112 for retaining an electronic device 180including the rechargeable battery 190 therein, and optionally mayinclude a second cradle 120 for receiving a second rechargeable battery190 therein. The at least one cradle 110, 120 of the housing 130 mayinclude: a guide member 114 for locating an electronic device 180including a rechargeable battery 190 therein and a pair of spring biasedarms 112 for retaining the electronic device 180 therein. Therechargeable battery 190 may be included in an electronic device 180that is configured to be retained in the at least one cradle 110, 120 ofthe housing 130. The at least one cradle 110, 120 of the housing 130 mayinclude first and second cradles 110, 120, the first cradle 110 beingconfigured to receive an electronic device 180 including a rechargeablebattery 190 therein and the second cradle 120 being configured toreceive a rechargeable battery 190 therein. The electrical circuit 20may include a DC converter 210 having an input coupled to one of thefirst and second receptacles 152, 154 and an output coupled to theelectrical contacts of the at least one cradle 110, 120. The DCconverter 210 may be coupled to the electrical contacts of the at leastone cradle 110, 120 by a circuit 220, 230, 240 providing a constantcurrent to charge a battery 180, 190 connected to the electricalcontacts of the at least one cradle 110, 120. The constant currentprovided to a rechargeable battery 180, 190 connected to the electricalcontacts of the at least one cradle 110, 120 may have a magnitudedetermined as a function of the open circuit voltage of the rechargeablebattery 180, 190. One or more guides 156, 400 may extend from thehousing 130 adjacent at least one of the first and second electricalreceptacles 152, 154 for aligning a mating connector 162, 164, 300 withrespect to the at least one of the first and second electricalreceptacles 152, 154. The one or more guides 156, 400 extending from thehousing 130 may have a groove 420: for aligning a rib 320 of a matingconnector 300 with respect to the at least one of the first and secondelectrical receptacles 152, 154, or for receiving a raised guide 330 ofa mating connector 300 for defining a single physical orientation formating the mating connector 300, or for aligning a rib 320 of a matingconnector 300 with respect to the at least one of the first and secondelectrical receptacles 152, 154 and for receiving a raised guide 330 ofa mating connector 300 for defining a single physical orientation formating the mating connector 300. The battery charger 100 may be incombination with an electronic device 180 including a rechargeablebattery 190 therein that is rechargeable in the at least one cradle 110,120 of the battery charger 100. The at least one cradle 110, 120 of thehousing 130 may include: one or more electrical contacts configured formaking electrical connection to a rechargeable battery 190; or one ormore electrical contacts configured for making electrical connection toan electronic device 180 including a rechargeable battery 190; or one ormore electrical contacts configured for making electrical connection toa rechargeable battery 190 and one or more electrical contactsconfigured for making electrical connection to an electronic device 180including a rechargeable battery 190. A first of the at least twoelectrical plug connectors 162, 164, 300 may be of a male or femalegender; or a second of the at least two electrical plug connectors 162,164, 300 may be of a male or female gender; or the first electricalreceptacle 152, 162 may be of a male or female gender; or the secondelectrical receptacle 152, 162 may be of a male or female gender; or anycompatible mate-able combination thereof. The battery charger 100 may bein combination with a power supply 168 having an electrical plugconnector 162, 164, 300 that is insertable into one of the first andsecond electrical receptacles of the battery charger 100. The housingmay include a sensor responsive to the temperature thereof and coupledto the electrical circuit. The electrical circuit 200 may be configuredto charge a rechargeable battery 180, 190 disposed in the at least onecradle 110, 120 by: a) setting 1400, 2070 an initial charge currentlevel that is substantially lower than a charge current that the battery180, 190 can accept; b) repetitively interrupting 1520, 2310, 2320charging 1500, 1520, 2315, 2325 of the battery 180, 190 at apredetermined timing to define a periodic cycle, and for each periodiccycle: measuring 1525, 2315, 2325 an open circuit voltage of the battery180, 190 when charging of the battery 180, 190 is interrupted,determining 1540-1580, 2335, 2345 from the measured open circuit voltageof the battery 180, 190 a corresponding predetermined level of chargingcurrent to be applied to the battery 180, 190; applying charging current1550, 2315, 2325, 2335, 2345 to the battery 180, 190 at thepredetermined level of charging current; and c) repeating 1550-1515,2355-2010, 2360-2010 the periodic cycle at least until the open circuitvoltage of the battery 180, 190 is at a predetermined voltage indicativeof the battery 180, 190 being fully charged or until the battery isdisconnected from the at least one cradle. One of the first and secondelectrical receptacles 152, 154 may include a connector guide 400, 156and wherein an electrical connector 164, 300 configured to matetherewith may comprise: an elongated connector body 310 defining alongitudinal direction and having an electrical cable 166 extending fromthe connector body 310; an electrical connector frame 164P at one end ofthe elongated connector body 310; a longitudinal alignment feature 320on the elongated connector body 310 configured for aligning theelongated connector body 310 with the connector guide 400, 156; a guidefeature 330 on the elongated connector body 310 defining a uniqueorientation of the elongated connector body 310; and a retaining feature340 on the elongated connector body 310 configured for retaining theelongated connector body 310 in the connector guide 400, 156, wherebythe elongated connector body 310 when inserted into the connector guide400, 156 is aligned with the connector guide 400, 156 by thelongitudinal alignment feature 320, is in the unique orientation definedby the guide feature 330 and is retained in the connector guide 400, 156by the retaining feature 340.

A connector 164, 300 may comprise: an elongated connector body 310defining a longitudinal direction and having an electrical cable 166extending from the connector body 310; an electrical connector frame164P at one end of the elongated connector body 310; a longitudinalalignment feature 320 on the elongated connector body 310 configured foraligning the elongated connector body 310 with a connector guide 156,400; a guide feature 330 on the elongated connector body 310 defining aunique orientation of the elongated connector body 310; and a retainingfeature 340 on the elongated connector body 310 configured for retainingthe elongated connector body 310 in the connector guide 165, 400,whereby the elongated connector body 310 when inserted into theconnector guide 156, 400 may be aligned with the connector guide 156,400 by the longitudinal alignment feature 320, may be in the uniqueorientation defined by the guide feature 330 and may be retained in theconnector guide by the retaining feature 340. The longitudinal alignmentfeature 320 may include a raised longitudinal rib 320; or the guidefeature 330 may include a raised guide member 330; or the longitudinalalignment feature 320 may include a raised longitudinal rib 320 and theguide feature 330 may include a raised guide member 330; or theretaining feature 340 may include at least one raised transverse rib340; or the longitudinal alignment feature 320 may include a raisedlongitudinal rib 320 and the retaining feature 340 may include at leastone raised transverse rib 340; or the guide feature 330 may include araised guide member 330 and the retaining feature 340 may include atleast one raised transverse rib 340; or the longitudinal alignmentfeature 320 may include a raised longitudinal rib 320 and the guidefeature 330 may include a raised guide member 330 and the retainingfeature 340 may include at least one raised transverse rib 340. Theconnector 164, 300 may be in combination with a connector guide 156,400, the connector guide 400 may comprise: one or more guide members400, 156 extending outwardly from a base 130, 130B adjacent a matingconnector 152, 154 for the electrical connector frame 164P; the one ormore guide members 400, 156 configured to be adjacent to the elongatedconnector body 310 to align the elongated connector body 310 and themating connector 152, 154 when the electrical connector frame 164P mateswith the mating connector 152, 154. The one or more guide members 400,156 may have: a longitudinal alignment guide 420 complementary to thelongitudinal alignment feature 320 of the elongated connector body 310;the longitudinal alignment guide 420 being configured to receive theguide feature 320 on the elongated connector body 310 when the elongatedconnector body 310 is in the defined unique orientation; a complementaryretaining feature 440 configured to receive the retaining feature 340 onthe elongated connector body 310 for retaining the elongated connectorbody 310 in the connector guide 156, 400 and mated to the matingconnector 152, 154. The longitudinal alignment feature 320 on theelongated connector body 310 may include a raised alignment rib 320configured for aligning with a groove 420 on an inward facing surface ofthe one or more guide members 156 of the connector guide 156, 400; theguide feature 330 on the elongated connector body 310 may include araised guide 330 defining a unique orientation of the elongatedconnector body 310 and engages the groove 320 on an inward facingsurface of the one or more guide members 156, 400; and the retainingfeature 340 on the elongated connector body 310 may be a raised rib 340or a recess 340 that engages a complementary recess 340 or raised rib340 on an inward facing surface of the one or more guide members 156,400. The connector body 310 may be a slip fit with the connector guide156, 400 and the retaining feature 340 may be an interference fit or asnap fit with the connector guide 156, 400. The connector body 310 maybe a slip fit with the connector guide 400, 156 and the retainingfeature 340 may be an interference fit or a snap fit with the connectorguide 400, 156. The connector frame 164P may include a USB connectorframe 164P. The electrical connector 300, 400 may be configured toconnect an external electrical power supply 168 to a charger housing100, and the charger housing 100, 130 may include an electronic circuit200 for determining the level of current available from the externalpower supply 168 via the electrical connector 300, 400, 152, 154including: measuring 1200, 2350 a voltage provided by the external powersupply 168; determining 1200, 2350 whether the voltage provided by theexternal power supply 168 is less than a predetermined voltage and, ifso: decreasing 1250, 2355 the current drawn from the external powersupply 168 by a predetermined amount; repeating the foregoing steps ofmeasuring 1200, 2350, determining 1200, 2350 and decreasing 1250, 2355until the voltage provided by the external power supply 168 is not lessthan the predetermined voltage. The electrical connector 300, 400 may beconfigured to connect a first external power supply 168 to a firstelectrical connector 152, 154 of a charger housing 130: the chargerhousing 130 including a second electrical connector 154, 152 configuredfor receiving electrical power from a second external electrical powersupply 168, wherein the first electrical connector 152 and the secondelectrical connector 154 are closely adjacent each other such that anexternal electrical connector 162, 164, 300, 400 mated with the firstelectrical connector 152 or with the second electrical connector 154physically interferes with and prevents an external electrical connectorfrom being mated with the other of the first electrical connector 152and the second electrical connector 154.

An electrical connector 154, 400 may comprise: an electrical connectorframe 154 supported on a base 130, 130B and defining a longitudinaldirection extending from the base 130, 130B; an alignment and retainingstructure 400 including first and second opposing guide members 156extending from the base 130, 130B in the longitudinal direction, thefirst and second opposing guide members 156 each having an inward facingsurface that faces the other guide member 156, wherein the first andsecond guide members 156 are located spaced apart by a distanceconfigured for an elongated connector body 310 to be placed therebetweenwith an electrical connector frame 164P of the elongated connector body310 positioned to mate with the electrical connector frame 154 supportedon the base 130, 130B; the first guide member 156 having on the inwardfacing surface thereof a longitudinal alignment feature 420 configuredto align a complementary longitudinal alignment feature 320 of theconnector body 310 with the electrical connector frame 154 supported onthe base 130, 130B, wherein the longitudinal alignment feature 420 ofthe first guide member 156 is configured to receive a guide feature 330on the elongated connector body 310 that defines a unique orientation ofthe elongated connector body 310; and at least one of the first andsecond guide members 156 having on the inward facing surface thereof aretaining feature 440 configured to engage a complementary retainingfeature 340 of the elongated connector body 310 for retaining theelongated connector body 310 between the first and second guide members156 with the electrical connector frame 164P of the elongated connectorbody 310 mated with the electrical connector frame 154 supported by thebase 130, 130B, whereby the elongated connector body 310 when insertedto mate with the electrical connector frame 154 supported by the base130, 130B is aligned therewith by the complementary longitudinalalignment features 320, 420, is in the unique orientation defined by theguide feature 330 and is retained between the first and second guidemembers 156 by the complementary retaining features 340, 440. Thelongitudinal alignment feature 420 of the first guide member 156 mayinclude a longitudinal groove 420; or the retaining feature 440 of theat least one of the first and second guide members 156 may include atransverse rib or groove 440; or the longitudinal alignment feature 420of the first guide member 156 may include a longitudinal groove 420 andthe retaining feature 440 of the at least one of the first and secondguide members 156 may include a transverse rib or groove 440. Theelectrical connector 154, 400 in combination with a mating electricalconnector 164, 300 which may comprise: an elongated connector body 310in the longitudinal direction and having an electrical cable 166extending from the connector body 310; an electrical connector frame164P at one end of the elongated connector body 310; a longitudinalalignment feature 420 on the elongated connector body 310 configured foraligning the elongated connector body 310 with the alignment feature 420of the first guide member 156; a guide feature 330 on the elongatedconnector body 310 defining a unique orientation of the elongatedconnector body 310; and a retaining feature 340 on the elongatedconnector body 310 configured for engaging the at least one of the firstand second guide members 156 for retaining the elongated connector body310 in the first and second guide members 156, whereby the elongatedconnector body 310 when inserted between the first and second guidemembers 156 so that when the respective electrical connector frames 154,164P thereof are mated the connector body 310 is aligned by therespective longitudinal alignment features 320, 420, is in the uniqueorientation defined by the guide feature 320 and is retained between thefirst and second connector guide members 156 by the respective retainingfeatures 340, 440. The longitudinal alignment feature 420 of the firstguide member 156 may be configured to receive the guide feature 330 onthe elongated connector body 310 when the elongated connector body 310is in the defined unique orientation. The longitudinal alignment feature320 on the elongated connector body 310 may include a raised alignmentrib 320 configured for aligning with a groove 420 on the inward facingsurface of the first and second guide members 156; the guide feature 330on the elongated connector body 310 may include a raised guide 330 onthe alignment rib 320 defining a unique orientation of the elongatedconnector body 310 and may engage the groove 420 on the inward facingsurface of the first and second guide members 156; and the retainingfeature 340 on the elongated connector body 310 may be a raised rib 340or a recess 340 that engages a complementary recess 440 or raised rib440 on the inward facing surface of the first and second guide members156. The elongated connector body 310 may be a slip fit with the firstand second guide members 156 and the retaining feature 340 thereof maybe an interference fit or a snap fit with the retaining feature 440 ofthe at least one of the first and second guide members 156. Theelectrical connector frame 154, 164P may include a USB connector frame.The base 130, 130B may include a charger housing 130 and the electricalconnector frame 154 of the electrical connector 154 may be configuredfor receiving electrical power from an external electrical power supply168, the charger housing 130 may include an electronic circuit 200 fordetermining the level of current available from the external powersupply 168 via the electrical connector 154, 164, 300 including:measuring 1200, 2350 a voltage provided by the external power supply168; determining 1200, 2350 whether the voltage provided by the externalpower supply 168 is less than a predetermined voltage and, if so:decreasing 1250, 2355 the current drawn from the external power supply168 by a predetermined amount; repeating the foregoing steps ofmeasuring 1200, 2350, determining 1200, 2350 and decreasing 1250, 2355until the voltage provided by the external power supply 168 is not lessthan the predetermined voltage. The base 130, 130B may include a chargerhousing 130 and the electrical connector frame 154 of the electricalconnector 154 may be configured for receiving electrical power from afirst external electrical power supply 168, the charger housing 130 mayinclude a second electrical connector 152 configured for receivingelectrical power from a second external electrical power supply 168,wherein the electrical connector 154 and the second electrical connector152 are closely adjacent each other such that an external electricalconnector 164, 162 mated with the electrical connector 154 or with thesecond electrical connector 152 physically interferes with and preventsan external electrical connector 162, 164 from being mated with theother of the electrical connector 154 and the second electricalconnector 152.

An electrical connector 164, 300 may comprise: a substantiallyrectangular elongated connector body 310 defining a longitudinaldirection and having an electrical cable 166 extending from theelongated connector body 310; a USB connector frame 164P at one end ofthe elongated connector body 310; a longitudinal raised rib 320 on theelongated connector body 310 configured for aligning the elongatedconnector body 310 with a connector guide 400, 156 for a mating USBconnector 154; a raised guide feature 330 on the raised rib 320 of theelongated connector body 310 defining a unique orientation of theelongated connector body 310; and at least one transverse rib 340 ortransverse groove 340 on the elongated connector body 310 configured toengage the connector guide 400, 156 for retaining the elongatedconnector body 310 in the connector guide 400, 156, whereby theelongated connector body 310 when inserted into the connector guide 400,156 for the mating USB connector 154 is aligned with the connector guide400, 156 and the mating USB connector 154 by the longitudinal raised rib320, is in the unique orientation defined by the raised guide feature330 and is retained in the connector guide 400, 156 by the transverserib 340 or transverse groove 340. The retaining feature 340 may includeat least one raised transverse rib 340 and/or at least one transversegroove 340.

A pair of mating electrical connectors 154, 400, 164, 300 may comprise:a first electrical connector 164, 300 including: a substantiallyrectangular elongated connector body 310 defining a first longitudinaldirection and having an electrical cable 166 extending from theelongated connector body 310; a first USB connector frame 164P at oneend of the elongated connector body 310; a longitudinal raised rib 320on the elongated connector body 310 configured for aligning theelongated connector body 310 with a connector guide 400, 156 for amating USB connector 154; a raised guide feature 330 on the raised rib320 of the elongated connector body 310 defining a unique orientation ofthe elongated connector body 310; and at least one transverse rib 340 ortransverse groove 340 on the elongated connector body 310 configured toengage the connector guide 400, 156 for retaining the elongatedconnector body 310 in the connector guide 400, 156; and a secondelectrical connector 154, 400 including: a second USB electricalconnector frame 154 supported on a base 130, 130B and defining a secondlongitudinal direction extending from the base 130, 130B; an alignmentand retaining structure 400 including first and second opposing guidemembers 156 extending from the base 130, 130B in the second longitudinaldirection, the first and second opposing guide members 156 each havingan inward facing surface that faces the other guide member 156, whereinthe first and second guide members 156 are located spaced apart by adistance configured for the elongated connector body 310 to be placedtherebetween with the first USB electrical connector frame 164P of theelongated connector body 310 positioned to mate with the second USBelectrical connector frame 154 supported on the base 130, 130B, wherebythe first and second longitudinal directions are substantially aligned;the first guide member 156 having on the inward facing surface thereof alongitudinal groove 420 configured to align the complementarylongitudinal raised rib 320 of the connector body 310 with theelectrical connector frame 154 supported on the base 130, 130B, whereinthe longitudinal groove 420 of the first guide member 156 is configuredto receive the guide feature 330 on the elongated connector body 310that defines a unique orientation of the elongated connector body 310;and at least one of the first and second guide members 156 having on theinward facing surface thereof a transverse rib 440 or transverse groove440 configured to engage a complementary transverse groove 340 ortransverse rib 340 of the elongated connector body 310 for retaining theelongated connector body 310 between the first and second guide members156 with the first USB electrical connector frame 164P of the elongatedconnector body 310 mated with the second USB electrical connector frame154 supported by the base 130, 130B, whereby the first USB electricalconnector frame 164P of the elongated connector body 310 when insertedto mate with the second USB electrical connector frame 154 supported bythe base 130, 130B is aligned therewith by the complementarylongitudinal raised rib 320 and longitudinal groove 420, is in theunique orientation defined by the guide feature 330 and is retainedbetween the first and second guide members 156 by the complementarytransverse rib 340, 440 and transverse groove 340, 440, with the firstand second longitudinal directions substantially aligned.

A method 1100, 2000 for charging at least one rechargeable battery 180,190 connected to a battery charger 100 may comprise: a) determining1300, 2075, 2155 whether a battery 180, 190 is present; b) setting 1400,2070 an initial charge current level that is substantially lower than acharge current that the battery 180, 190 can accept; c) repetitivelyinterrupting 1500, 1520, 2315, 2325 charging of the battery 180, 190 ata predetermined timing to define a periodic cycle, and for each periodiccycle: measuring 1525, 2315, 2325 an open circuit voltage of the battery180, 190 when charging of the battery 180, 190 is interrupted 1500,1520, 2315, 2325, determining 1540-1590, 2335, 2345 from the measuredopen circuit voltage of the battery 180, 190 a correspondingpredetermined level of charging current to be applied to the battery180, 190; applying charging current 1550, 2315-2345 to the battery 180,190 at the predetermined level of charging current; and d) repeating theperiodic cycle 1500, 2000 at least until the open circuit voltage of thebattery 180, 190 is at a predetermined voltage indicative of the batterybeing fully charged 1580, 2085, 2165 or until the battery isdisconnected 1530, 2315, 2325 from the battery charger 100. A method1100, 2000 may further comprise determining 1200, 2350-2355 the level ofcurrent available from an external power supply 168 including: e)measuring 1200, 2350 a voltage provided by the external power supply; f)determining 1200, 2350 whether the voltage provided by the externalpower supply 168 is less than a predetermined voltage and, if so: g)decreasing 1250, 2355 the current drawn from the external power supply168 by a predetermined amount; h) repeating 1200, 2000 the foregoingsteps of e) measuring 1200, 2350, f) determining 1200, 2350 and g)decreasing 1250, 2355 until the voltage provided by the external powersupply 168 is not less than the predetermined voltage. The method 1100,2000 may further comprise setting 1250, 1545, 2360 a maximum chargecurrent for the battery 180, 190 that is equal to or less than the levelof current drawn from the external power supply 168 when the voltageprovided by the external power supply 168 is not less than thepredetermined voltage. In the method 1100, 2000, the initial chargecurrent level may be at a level of current that is safe for applying toa battery 180, 190 irrespective of its temperature, or irrespective ofits state of charge, or irrespective of its temperature and its state ofcharge. In the method 1100, 2000 the predetermined level of chargingcurrent to be applied to the battery 180, 190 may be substantially zero1580, 1590, 2230, 2255 when the measured 1525 open circuit voltage ofthe battery 180, 190 is greater than or equal to a voltage indicative offull charge for the battery 180, 190. The method 1100, 2000 may furthercomprise: reducing 1590, 2230, 2255 the charging current applied to thebattery 180, 190 substantially to zero for a period of time after theopen circuit voltage of the battery 180, 190 is at a predeterminedvoltage indicative of the battery 180, 190 being fully charged; orreducing 1590, 2230, 2255 the charging current applied to the batterysubstantially to zero for a predetermined period of time after the opencircuit voltage of the battery 180, 190 is at a predetermined voltageindicative of the battery 180, 190 being fully charged. The method 1100,2000 may further comprise: applying 2230, 2255 charging current to thebattery 180, 190 after the predetermined period of time or after thepredetermined period of time at least until the open circuit voltage ofthe battery 180, 190 is at a predetermined voltage indicative of thebattery being fully charged, thereby to top off the battery charge. Themethod 1100, 2000 with battery charger 100 in combination with anexternal source of electrical power 168 may further comprise: receivingelectrical power from the external source of electrical power 168 via afirst electrical connector 152, 154. The method 1100, 2000 may furthercomprise: employing a second electrical connector 152, 154 for receivingelectrical power from a second external source of electrical power 168,wherein the first and second electrical connectors 152, 154 are closelyadjacent each other such that an external electrical connector 162, 164,300 inserted into one of the first and second electrical connectors 152,154 physically interferes with and prevents an external electricalconnector 162, 164, 300 from being plugged into the other of the firstand second electrical connectors 152, 154. The first electricalconnector 154 may include a connector guide 400, 156 and an electricalconnector 164, 300 configured to mate therewith may comprise: anelongated connector body 310 defining a longitudinal direction andhaving an electrical cable 166 extending from the connector body 310; anelectrical connector frame 164P at one end of the elongated connectorbody 310; a longitudinal alignment feature 320 on the elongatedconnector body 310 configured for aligning the elongated connector body310 with the connector guide 400, 156; a guide feature 330 on theelongated connector body 310 defining a unique orientation of theelongated connector body 310; and a retaining feature 340 on theelongated connector body 310 configured for retaining the elongatedconnector body 310 in the connector guide 400, 156, whereby theelongated connector body 310 when inserted into the connector guide 400,156 is aligned with the connector guide 400, 156 by the longitudinalalignment feature 320, is in the unique orientation defined by the guidefeature 330 and is retained in the connector guide 400, 156 by theretaining feature 340.

A method 1100, 2000 for charging at least one rechargeable battery 180,190 connected to a battery charger 100 may comprise: a) determining1200, 2075, 2155 whether a battery is present; b) setting 1400, 2070 aninitial charge current level that is substantially lower than a chargecurrent that the battery 180, 190 can accept; c) determining 1200, 2305,2355 the level of current available from an external power supply 168including: i) measuring 1200, 2350 a voltage provided by the externalpower supply 168; ii) determining 1200, 2350 whether the voltageprovided by the external power supply 168 is less than a predeterminedvoltage and, if so: iii) decreasing 1250, 2355 the current drawn fromthe external power supply 168 by a predetermined amount; d) repeating1200, 2000 the foregoing steps of i) measuring 1200, 2350, determining1200, 2350 and iii) decreasing 1250, 2355 until the voltage provided bythe external power supply 168 is not less than the predeterminedvoltage. The method 1100, 2000 may further comprise setting 1250, 1545,2360 a maximum charge current for the battery 180, 190 that is equal toor less than the level of current drawn from the external power supply168 when the voltage provided by the external power supply 168 is notless than the predetermined voltage. The initial charge current levelmay be at a level of current that is safe for applying to a battery 180,190 irrespective of its temperature, or irrespective of its state ofcharge, or irrespective of its temperature and its state of charge. Themethod 1100, 2000 may further comprise: e) repetitively interrupting1500, 1520, 2315, 2325 charging of the battery 180, 190 at apredetermined timing to define a periodic cycle, and for each periodiccycle: measuring 1525, 2315, 2325 an open circuit voltage of the battery180, 190 when charging of the battery 180, 190 is interrupted 1520,2315, 2325, determining 1540-1590, 2335, 2345 from the measured opencircuit voltage of the battery 180, 190 a corresponding predeterminedlevel of charging current to be applied to the battery 180, 190;applying charging current 1550, 2315-2345 to the battery 180, 190 at thepredetermined level of charging current; and f) repeating the periodiccycle 1500, 2000 at least until the open circuit voltage of the battery180, 190 is at a predetermined voltage indicative of the battery 180,190 being fully charged or until the battery 180, 190 is disconnectedfrom the battery charger 100. The predetermined level of chargingcurrent to be applied to the battery 180, 190 may be substantially zerowhen the measured open circuit voltage of the battery 180, 190 isgreater than or equal to a voltage indicative of full charge for thebattery 180, 190. The method 1100, 2000 may further comprise: reducing1590, 2230, 2255 the charging current applied to the battery 180, 190substantially to zero for a period of time after the open circuitvoltage of the battery 180, 190 is at a predetermined voltage indicativeof the battery 180, 190 being fully charged; or reducing 1590, 2230,2255 the charging current applied to the battery 180, 190 substantiallyto zero for a predetermined period of time after the open circuitvoltage of the battery 180, 190 is at a predetermined voltage indicativeof the battery 180, 190 being fully charged. The method furthercomprises: applying 2230, 2255 charging current to the battery 180, 190after the predetermined period of time or after the predetermined periodof time at least until the open circuit voltage of the battery 180, 190is at a predetermined voltage indicative of the battery 180, 190 beingfully charged, thereby to top off the battery charge. The method 1100,2000 with battery charger 100 in combination with an external source ofelectrical power 168 may further comprise: receiving electrical powerfrom the external source of electrical power 168 via a first electricalconnector 152, 154. The method 1100, 2000 may further comprise:employing a second electrical connector 152, 154 for receivingelectrical power from a second external source of electrical power 168,wherein the first and second electrical connectors 152, 154 are closelyadjacent each other such that an external electrical connector 162, 164,300 inserted into one of the first and second electrical connectors 152,154 physically interferes with and prevents an external electricalconnector 162, 164, 300 from being plugged into the other of the firstand second electrical connectors 152, 154. The first electricalconnector may include a connector guide 400, 16 and an electricalconnector 162, 164, 300 configured to mate therewith may comprise: anelongated connector body 310 defining a longitudinal direction andhaving an electrical cable 166 extending from the connector body 310; anelectrical connector frame 164P at one end of the elongated connectorbody 310; a longitudinal alignment feature 320 on the elongatedconnector body 310 configured for aligning the elongated connector body310 with the connector guide 400, 156; a guide feature 330 on theelongated connector body 310 defining a unique orientation of theelongated connector body 310; and a retaining feature 340 on theelongated connector body 310 configured for retaining the elongatedconnector body 310 in the connector guide 400, 156, whereby theelongated connector body 310 when inserted into the connector guide 400,156 is aligned with the connector guide 400, 156 by the longitudinalalignment feature 320, is in the unique orientation defined by the guidefeature 320 and is retained in the connector guide 400, 156 by theretaining feature 340.

A method 1100, 2000 for charging at least one rechargeable battery 180,190 connected to a battery charger 100 may comprise: a) determining1300, 2075, 2155 whether a battery 180, 190 is present; b) setting 1400,2070 an initial charge current level that is substantially lower than acharge current that the battery 180, 190 can accept;

c) determining 1200, 2305, 2355 the level of current available from anexternal power supply 168 including: i) measuring 1200, 2350 a voltageprovided by the external power supply 168; ii) determining 1200, 2350whether the voltage provided by the external power supply 168 is lessthan a predetermined voltage and, if so: iii) decreasing 1250, 2355 thecurrent drawn from the external power supply 168 by a predeterminedamount; d) repeating 1200, 2000 the foregoing steps of i) measuring1200, 2350, ii) determining 1200, 2350 and iii) decreasing 1250, 2355until the voltage provided by the external power supply 168 is not lessthan the predetermined voltage; and e) repetitively interrupting 1500,1520, 2315, 2325 charging of the battery 180, 190 at a predeterminedtiming to define a periodic cycle, and for each periodic cycle: i)measuring 1525, 2315, 2325 an open circuit voltage of the battery 180,190 when charging of the battery 180, 190 is interrupted 1500, 1520,2315, 2325, ii) determining 1540-1590, 2335, 2345 from the measured opencircuit voltage of the battery 180, 190 a corresponding predeterminedlevel of charging current to be applied to the battery 180, 190; iii)applying charging current 1550, 2315-2345 to the battery 180, 190 at thepredetermined level of charging current; and f) repeating the periodiccycle 1500, 2000 at least until the open circuit voltage of the battery180, 190 is at a predetermined voltage indicative of the battery beingfully charged 1580, 2085, 2165 or until the battery is disconnected1530, 2315, 2325 from the battery charger 100.

As used herein, the term “about” means that dimensions, sizes,formulations, parameters, shapes and other quantities andcharacteristics are not and need not be exact, but may be approximateand/or larger or smaller, as desired, reflecting tolerances, conversionfactors, rounding off, measurement error and the like, and other factorsknown to those of skill in the art. In general, a dimension, size,formulation, parameter, shape or other quantity or characteristic is“about” or “approximate” whether or not expressly stated to be such. Itis noted that embodiments of very different sizes, shapes and dimensionsmay employ the described arrangements.

As used herein, the terms “electrical receptacle connector” and“electrical receptacle” and “receptacle” refers to an electricalconnector and/or contacts, whether of the male or female type or ofmixed types, that is associated with charger base or housing, e.g.,typically disposed in a connector port thereof for receiving anelectrical plug; and the terms “electrical plug connector” and“electrical plug” and “plug” refers to an electrical connector, whetherof the male or female type or of mixed types, that is associated with anelectrical power supply, e.g., with a housing thereof and/or a cablethereof.

Although terms such as “up,” “down,” “left,” “right,” “up,” “down,”“front,” “rear,” “side,” “end,” “top,” “bottom,” “forward,” “backward,”“under” and/or “over,” “vertical,” “horizontal,” and the like may beused herein as a convenience in describing one or more embodimentsand/or uses of the present arrangement, the articles described may bepositioned in any desired orientation and/or may be utilized in anydesired position and/or orientation. Such terms of position and/ororientation should be understood as being for convenience only, and notas limiting of the invention as claimed.

The term battery is used herein to refer to an electro-chemical devicecomprising one or more electro-chemical cells and/or fuel cells, and soa battery may include a single cell or plural cells, whether asindividual units or as a packaged unit. A battery is one example of atype of an electrical power source suitable for a portable or otherdevice. Such devices could include power sources including, but notlimited to, fuel cells, super capacitors, solar cells, and the like. Anyof the foregoing may be intended for a single use or for beingrechargeable or for both. The term battery 190 may be used to describe abattery 190 that is disposed in a flashlight 180 (as may be placed intoa flashlight cradle, e.g., cradle 110), or a battery 190 not in aflashlight (as may be placed into a secondary cradle, e.g., cradle 120).

Various embodiments of a battery may have one or more battery cells,e.g., one, two, three, four, or five or more battery cells, as may bedeemed suitable for any particular device. A battery may employ varioustypes and kinds of battery chemistry types, e.g., a carbon-zinc,alkaline, lead acid, nickel-cadmium (Ni—Cd), nickel-metal-hydride (NiMH)or lithium-ion (Li-Ion) battery type, of a suitable number of cells andcell capacity for providing a desired operating time and/or lifetime fora particular device, and may be intended for a single use or for beingrechargeable or for both. Examples may include a two cell lead acidbattery typically producing about 4 volts, a three cell Ni—Cd batterytypically producing about 3.6 volts, a four cell NiMH battery typicallyproducing about 4.8 volts, a Lithium-Ion battery typically producingabout 2.5 to 4.2 volts, it being noted that the voltages producedthereby will be higher when approaching full charge and will be lowerwhen not fully charged and in discharge, particularly when providinghigher current and when reaching a low level of remaining charge, e.g.,becoming discharged.

The term DC converter is used herein to refer to any electronic circuitthat receives at an input electrical power at one voltage and currentlevel and provides at an output DC electrical power at a differentvoltage and/or current level. Examples may include a DC-DC converter, anAC-DC converter, a boost converter, a buck converter, a buck-boostconverter, a single-ended primary-inductor converter (SEPIC), a seriesregulating element, a current level regulator, and the like. The inputand output thereof may be DC coupled and/or AC coupled, e.g., as by atransformer and/or capacitor. A DC converter may or may not includecircuitry for regulating a voltage and/or a current level, e.g., at anoutput thereof, and may have one or more outputs providing electricalpower at different voltage and/or current levels and/or in differentforms, e.g., AC or DC.

While the present invention has been described in terms of the foregoingexample embodiments, variations within the scope and spirit of thepresent invention as defined by the claims following will be apparent tothose skilled in the art. For example, while charger 100 is shown ashaving a cradle 110 configured to receive an electronic device, e.g., aflashlight, including a rechargeable battery and a cradle 120 (which canbe optional) configured to receive a rechargeable battery, either cradle110 or cradle 120 or both of cradles 110 and 120 can be configured toreceive an electronic device, or to receive a rechargeable battery.

Further, either cradle 110 or cradle 120 or both of cradles 110 and 120can be configured to receive an electronic device and a rechargeablebattery one at a time, e.g., with suitable electrical contacts and/orpositioning guides provided for cradle 110 and/or cradle 120. In otherwords, an electronic device can be placed into cradle 110 for rechargingthe battery therein or a battery apart from an electronic device can beplaced into cradle 110 for recharging, cradle 110 being configured tohave electrical contacts for making electrical connection to theelectronic device and for making electrical contacts to the battery. Inaddition, cradle 120, if provided, may be similarly configured withelectrical contacts for making electrical connection to an electronicdevice and to a battery.

Regarding connector port 150, while two different generally rectangularreceptacles for receiving power supply plugs are illustrated, thedifferent receptacles could be rectangular, square, trapezoidal,circular, oval, triangular, or any other shape. The mating plugs andreceptacles may have complementary male pins, female pins, or acombination thereof, and may be of similar shape or of dissimilar shape.

Further, where a particular type of connector is shown, e.g., a USBconnector, another type of connector could be provided The term USBconnector is considered to encompass both plugs and receptacles, type Aand B USB connectors, versions 1.x, 2.x and 3.x, and all other varietiesthereof. Similarly, the relative positions of male and femaleconnectors, e.g., receptacles and plugs, can be interchanged unlessspecifically stated otherwise, and further, a plug may be of either themale gender or the female gender and a receptacle may be of either themale gender or the female gender.

While the example electronic device 180 has an electrical switch 188S inthe tail cap 186T thereof, the electrical switch could be locatedinternally forward of battery 190 and actuator 188 could move battery190 forward so that the forward end thereof actuates an electricalswitch associated, e.g., with circuit board thereof, or a switch and/oractuator could be provided on another location on light 180.

Raised and recess features intended to engage may be interchanged, e.g.,a raised feature may be provided where a recess feature is shown hereinand a corresponding recess feature may be provided where a correspondingraised feature is shown. Alternatively, raised and recessed features mayboth be utilized, e.g., as for retaining features 340 of connector 300and the complementary retaining features 440 of guides 156, 400.

While certain features may be described as a raised feature, e.g., aridge, boss, flange, projection or other raised feature, such featuremay be positively formed or may be what remains after a recessedfeature, e.g., a groove, slot, hole, indentation, recess or otherrecessed feature, is made. Similarly, while certain features may bedescribed as a recessed feature, e.g., a groove, slot, hole,indentation, recess or other recessed feature, such feature may bepositively formed or may be what remains after a raised feature, e.g., aridge, boss, flange, projection or other raised feature, is made.

While connector body 310 is substantially rectangular as illustrated,with various features 312, 320, 330, 340 added thereto, other shapescould also be employed, e.g., substantially cylindrical with a circular,elliptical or oval cross-section, triangular, hexagonal, and so forth.

Each of the U.S. Provisional Applications, U.S. patent applications,and/or U.S. patents, identified herein is hereby incorporated herein byreference in its entirety, for any purpose and for all purposesirrespective of how it may be referred to or described herein.

Finally, numerical values stated are typical or example values, are notlimiting values, and do not preclude substantially larger and/orsubstantially smaller values. Values in any given embodiment may besubstantially larger and/or may be substantially smaller than theexample or typical values stated.

What is claimed is:
 1. A method for charging at least one rechargeablebattery connected to a battery charger, the method comprising: a)determining whether a battery is present; b) setting an initial chargecurrent level that is substantially lower than a charge current that thebattery can accept; c) repetitively interrupting charging of the batteryat a predetermined timing to define a periodic cycle, and for eachperiodic cycle: measuring an open circuit voltage of the battery whencharging of the battery is interrupted, determining from the measuredopen circuit voltage of the battery a corresponding predetermined levelof charging current to be applied to the battery; applying chargingcurrent to the battery at the predetermined level of charging current;and d) repeating the periodic cycle of step c) at least until the opencircuit voltage of the battery is at a predetermined voltage indicativeof the battery being fully charged or until the battery is disconnectedfrom the battery charger.
 2. The method of claim 1 further comprisingdetermining the level of current available from an external power supplyincluding: e) measuring a voltage provided by the external power supply;f) determining whether the voltage provided by the external power supplyis less than a predetermined voltage and, if so: g) decreasing thecurrent drawn from the external power supply by a predetermined amount;h) repeating the foregoing steps of e) measuring, f) determining and g)decreasing until the voltage provided by the external power supply isnot less than the predetermined voltage.
 3. The method of claim 2further comprising setting a maximum charge current for the battery thatis: equal to or less than the level of current available from theexternal power supply; or equal to or less than the level of currentdrawn from the external power supply when the voltage provided by theexternal power supply is not less than the predetermined voltage.
 4. Themethod of claim 1 wherein the initial charge current level is at a levelof current that is safe for applying to a battery irrespective of itstemperature, or irrespective of its state of charge, or irrespective ofits temperature and its state of charge.
 5. The method of claim 1wherein the initial charge current level is substantially zero iftemperature is not within a predetermined range of temperature or ifbattery voltage is at or above the predetermined voltage indicative ofthe battery being fully charged.
 6. The method of claim 5 whereinthereafter the charge current is set to a predetermined test currentlevel to verify that the battery is in a condition to accept charging inaccordance with steps c) and d) of claim
 1. 7. The method of claim 1wherein the predetermined level of charging current to be applied to thebattery is substantially zero when the measured open circuit voltage ofthe battery is greater than or equal to a voltage indicative of fullcharge for the battery.
 8. The method of claim 1 further comprising:reducing the charging current applied to the battery substantially tozero for a period of time after the open circuit voltage of the batteryis at a predetermined voltage indicative of the battery being fullycharged; or reducing the charging current applied to the batterysubstantially to zero for a predetermined period of time after the opencircuit voltage of the battery is at a predetermined voltage indicativeof the battery being fully charged.
 9. The method of claim 8 furthercomprising: applying charging current to the battery after thepredetermined period of time; or applying charging current to thebattery after the predetermined period of time at least until the opencircuit voltage of the battery is at a predetermined voltage indicativeof the battery being fully charged, thereby to top off the batterycharge.
 10. The method of claim 1 with the battery charger incombination with an external source of electrical power, said methodfurther comprising: receiving electrical power from the external sourceof electrical power via a first electrical connector.
 11. The method ofclaim 10 further comprising: employing a second electrical connector forreceiving electrical power from a second external source of electricalpower, wherein the first and second electrical connectors are closelyadjacent each other such that an external electrical connector insertedinto one of said first and second electrical connectors physicallyinterferes with and prevents an external electrical connector from beingplugged into the other of said first and second electrical connectors.12. The method of claim 10 wherein said first electrical connectorincludes a connector guide and wherein an electrical connectorconfigured to mate therewith comprises: an elongated connector bodydefining a longitudinal direction and having an electrical cableextending from the connector body; an electrical connector frame at oneend of said elongated connector body; a longitudinal alignment featureon said elongated connector body configured for aligning said elongatedconnector body with the connector guide; a guide feature on saidelongated connector body defining a unique orientation of said elongatedconnector body; and a retaining feature on said elongated connector bodyconfigured for retaining said elongated connector body in the connectorguide, whereby said elongated connector body when inserted into theconnector guide is aligned with the connector guide by the longitudinalalignment feature, is in the unique orientation defined by said guidefeature and is retained in the connector guide by said retainingfeature.
 13. A method for charging at least one rechargeable batteryconnected to a battery charger, the method comprising: a) determiningwhether a battery is present; b) setting an initial charge current levelthat is substantially lower than a charge current that the battery canaccept; c) determining the level of current available from an externalpower supply including: i) measuring a voltage provided by the externalpower supply; ii) determining whether the voltage provided by theexternal power supply is less than a predetermined voltage and, if so:iii) decreasing the current drawn from the external power supply by apredetermined amount; d) repeating the foregoing steps of i) measuring,ii) determining and iii) decreasing of step c) until the voltageprovided by the external power supply is not less than the predeterminedvoltage.
 14. The method of claim 13 further comprising setting a maximumcharge current for the battery that is: equal to or less than the levelof current available from the external power supply; or equal to or lessthan the level of current drawn from the external power supply when thevoltage provided by the external power supply is not less than thepredetermined voltage.
 15. The method of claim 13 wherein the initialcharge current level is at a level of current that is safe for applyingto a battery irrespective of its temperature, or irrespective of itsstate of charge, or irrespective of its temperature and its state ofcharge.
 16. The method of claim 13 further comprising: e) repetitivelyinterrupting charging of the battery at a predetermined timing to definea periodic cycle, and for each periodic cycle: measuring an open circuitvoltage of the battery when charging of the battery is interrupted,determining from the measured open circuit voltage of the battery acorresponding predetermined level of charging current to be applied tothe battery; applying charging current to the battery at thepredetermined level of charging current; and f) repeating the periodiccycle of step e) at least until the open circuit voltage of the batteryis at a predetermined voltage indicative of the battery being fullycharged or until the battery is disconnected from the battery charger.17. The method of claim 16 wherein the initial charge current level issubstantially zero if temperature is not within a predetermined range oftemperature or if battery voltage is at or above the predeterminedvoltage indicative of the battery being fully charged.
 18. The method ofclaim 17 wherein thereafter the charge current is set to a predeterminedtest current level to verify that the battery is in a condition toaccept charging in accordance with steps c) and d) of claim
 13. 19. Themethod of claim 16 wherein the predetermined level of charging currentto be applied to the battery is substantially zero when the measuredopen circuit voltage of the battery is greater than or equal to avoltage indicative of full charge for the battery.
 20. The method ofclaim 16 further comprising: reducing the charging current applied tothe battery substantially to zero for a period of time after the opencircuit voltage of the battery is at a predetermined voltage indicativeof the battery being fully charged; or reducing the charging currentapplied to the battery substantially to zero for a predetermined periodof time after the open circuit voltage of the battery is at apredetermined voltage indicative of the battery being fully charged. 21.The method of claim 20 further comprising: applying charging current tothe battery after the predetermined period of time; or applying chargingcurrent to the battery after the predetermined period of time at leastuntil the open circuit voltage of the battery is at a predeterminedvoltage indicative of the battery being fully charged, thereby to topoff the battery charge.
 22. The method of claim 13 with the batterycharger in combination with an external source of electrical power, saidmethod further comprising: receiving electrical power from the externalsource of electrical power via a first electrical connector.
 23. Themethod of claim 22 further comprising: employing a second electricalconnector for receiving electrical power from a second external sourceof electrical power, wherein the first and second electrical connectorsare closely adjacent each other such that an external electricalconnector inserted into one of said first and second electricalconnectors physically interferes with and prevents an externalelectrical connector from being plugged into the other of said first andsecond electrical connectors.
 24. The method of claim 22 wherein saidfirst electrical connector includes a connector guide and wherein anelectrical connector configured to mate therewith comprises: anelongated connector body defining a longitudinal direction and having anelectrical cable extending from the connector body; an electricalconnector frame at one end of said elongated connector body; alongitudinal alignment feature on said elongated connector bodyconfigured for aligning said elongated connector body with the connectorguide; a guide feature on said elongated connector body defining aunique orientation of said elongated connector body; and a retainingfeature on said elongated connector body configured for retaining saidelongated connector body in the connector guide, whereby said elongatedconnector body when inserted into the connector guide is aligned withthe connector guide by the longitudinal alignment feature, is in theunique orientation defined by said guide feature and is retained in theconnector guide by said retaining feature.
 25. A method for charging atleast one rechargeable battery connected to a battery charger, themethod comprising: a) determining whether a battery is present; b)setting an initial charge current level that is substantially lower thana charge current that the battery can accept; c) determining the levelof current available from an external power supply including: i)measuring a voltage provided by the external power supply; ii)determining whether the voltage provided by the external power supply isless than a predetermined voltage and, if so: iii) decreasing thecurrent drawn from the external power supply by a predetermined amount;d) repeating the foregoing steps of i) measuring, ii) determining andiii) decreasing of step c) until the voltage provided by the externalpower supply is not less than the predetermined voltage; and e)repetitively interrupting charging of the battery at a predeterminedtiming to define a periodic cycle, and for each periodic cycle: i)measuring an open circuit voltage of the battery when charging of thebattery is interrupted, ii) determining from the measured open circuitvoltage of the battery a corresponding predetermined level of chargingcurrent to be applied to the battery; iii) applying charging current tothe battery at the predetermined level of charging current; and f)repeating the steps i) measuring, ii) determining and iii) applying ofthe periodic cycle of step e) at least until the open circuit voltage ofthe battery is at a predetermined voltage indicative of the batterybeing fully charged or until the battery is disconnected from thebattery charger.